Compounds

ABSTRACT

The present invention relates to therapeutically active xanthine derivative compounds of Formula (I): 
                         
corresponding processes for manufacture of said derivatives, pharmaceutical formulations containing and uses of such compounds in therapy, particularly in treatment of diseases where under-activation of the HM74A receptor contributes to the disease or where activation of the receptor will be beneficial.

CROSS REFERENCE TO PRIOR APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/589,474, which was filed Aug. 14, 2006 and is a §371 of the PCTInternational Application No.: PCT/EP2005/001449. This application alsois related to U.S. application Ser. No. 12/552,649, which was filed onSep. 2, 2009, which is a continuation of U.S. application Ser. No.10/589,474, which was filed Feb. 10, 2005.

FIELD OF THE INVENTION

The present invention relates to therapeutically active compounds whichare xanthine derivatives, processes for the manufacture of saidderivatives, pharmaceutical formulations containing the active compoundsand the use of the compounds in therapy, particularly in the treatmentof diseases where under-activation of the HM74A receptor contributes tothe disease or where activation of the receptor will be beneficial.

BACKGROUND OF THE INVENTION

Dyslipidaemia is a general term used to describe individuals withaberrant lipoprotein profiles. Clinically, the main classes of compoundsused for the treatment of patients with dyslipidaemia, and therefore atrisk of cardiovascular disease are the statins, fibrates, bile-acidbinding resins and nicotinic acid. Nicotinic acid (Niacin, a B vitamin)has been used clinically for over 40 years in patients with variousforms of dyslipidaemia. The primary mode of action of nicotinic acid isvia inhibition of hormone-sensitive triglyceride lipase (HSL), whichresults in a lowering of plasma non-esterified fatty acids (NEFA) whichin turn alters hepatic fat metabolism to reduce the output of LDL andVLDL (low and very low density lipoprotein). Reduced VLDL levels arethought to lower cholesterol ester transfer protein (CETP) activity toresult in increased HDL (high density lipoprotein) levels which may bethe cause of the observed cardiovascular benefits. Thus, nicotinic acidproduces a very desirable alteration in lipoprotein profiles; reducinglevels of VLDL and LDL whilst increasing HDL. Nicotinic acid has alsobeen demonstrated to have disease modifying benefits, reducing theprogression and increasing the regression of atherosclerotic lesions andreducing the number of cardiovascular events in several trials.

The observed inhibition of HSL by nicotinic acid treatment is mediatedby a decrease in cellular cyclic adenosine monophosphate (cAMP) causedby the G-protein-mediated inhibition of adenylyl cyclase. Recently, theG-protein coupled receptors HM74 and HM74A have been identified asreceptors for nicotinic acid (PCT patent application WO02/84298; Wiseet. al. J Biol. Chem., 2003, 278 (11), 9869-9874). The DNA sequence ofhuman HM74A may be found in Genbank; accession number AY148884. Twofurther papers support this discovery, (Tunaru et. al. Nature Medicine,2003, 9(3), 352-255 and Soga et. al. Biochem Biophys Res Commun., 2003,303 (1) 364-369), however the nomenclature differs slightly. In theTunaru paper what they term human HM74 is in fact HM74A and in the Sogapaper HM74b is identical to HM74A. Cells transfected to express HM74Aand/or HM74 gain the ability to elicit G_(i) G-protein mediatedresponses following exposure to nicotinic acid. In mice lacking thehomologue of HM74A (m-PUMA-G) nicotinic acid fails to reduce plasma NEFAlevels.

Certain xanthine derivatives have been synthesised and disclosed in theprior art. For example, EP0389282 discloses xanthine derivatives aspotential mediators of cerebrovascular disorders. A range of xanthinederivatives were identified as adenosine receptor antagonists byJacobson et. al. in J. Med. Chem., 1993, 36, 2639-2644.

We now present a group of xanthine derivatives which are selectiveagonists of the nicotinic acid receptor HM74A and are thus of benefit inthe treatment, prophylaxis and suppression of diseases whereunder-activation of this receptor either contributes to the disease orwhere activation of the receptor will be beneficial.

SUMMARY OF THE INVENTION

The present invention provides therapeutically active xanthinederivatives and the use of these derivatives in therapy, particularly inthe treatment of diseases where under-activation of the HM74A receptorcontributes to the disease or where activation of the receptor will bebeneficial, in particular diseases of lipid metabolism includingdyslipidaemia or hyperlipoproteinaemia such as diabetic dyslipidaemiaand mixed dyslipidaemia, heart failure, hypercholesteraemia,cardiovascular disease including atherosclerosis, arteriosclerosis, andhypertriglyceridaemia. As such, the compounds may also find favour astherapeutics for coronary artery disease, thrombosis, angina, chronicrenal failure, peripheral vascular disease and stroke, as well as thecardiovascular indications associated with type II diabetes mellitus,type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa,obesity. The compounds may also be of use in the treatment ofinflammatory diseases or conditions, as set out further below.

Intermediates, formulations, methods and processes described herein formfurther aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

According to one aspect of this invention, we provide a compound ofFormula (I)

and a physiologically functional derivative thereof, whereinR¹ is selected from: hydrogen and C₁₋₄ alkyl which may be optionallysubstituted with one or more groups selected from CN and CF₃;R² is selected from: C₃₋₁₀ unsubstituted alkyl, C₁₋₁₀ alkyl substitutedwith one or more groups selected from fluorine and CN, C₅ alkenyl,unbranched C₄ alkenyl, and C₁₋₄ alkyl substituted with cycloalkyl;and R³ is selected from halogen and CN;with the proviso that:(i) when R³ represents Cl, and R¹ represents ethyl, R² is other thanpropyl;(ii) when R³ represents Br, and R¹ represents propyl, R² is other thanpropyl;(iii) when R³ represents Cl or Br, and R¹ represents butyl, R² is otherthan butyl; and(iv) when R¹ represents C₁₋₄ alkyl, CH₂CN, or (CH₂)₃CF₃, R² is otherthan branched alkyl.

The compounds are of use in the treatment of diseases whereunder-activation of the HM74A receptor contributes to the disease orwhere activation of the receptor will be beneficial, in particulardiseases of lipid metabolism including dyslipidaemia orhyperlipoproteinaemia such as diabetic dyslipidaemia and mixeddyslipidaemia, heart failure, hypercholesteraemia, cardiovasculardisease including atherosclerosis, arteriosclerosis, andhypertriglyceridaemia. As such, the compounds may also find favour astherapeutics for coronary artery disease, thrombosis, angina, chronicrenal failure, peripheral vascular disease and stroke, as well as thecardiovascular indications associated with type II diabetes mellitus,type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa,obesity. As such the compounds of the present invention may find use asagonists or partial agonists of HM74A (HM74A modulators).

In particular embodiments, R¹ is selected from: hydrogen, C₁₋₄ alkyl,CH₂CN and (CH₂)₃CF₃; In more particular embodiments R¹ is selected from:hydrogen and methyl.

In certain embodiments, R² is selected from: C₃₋₁₀ unsubstituted alkyl,C₁₋₆alkyl with one or more CN substitutions, C₁₋₁₀ alkyl with one ormore fluorine substitutions, C₅ alkenyl, unbranched C₄ alkenyl, and C₁₋₄alkyl substituted with cycloalkyl. Particularly R² is selected from:C₃₋₁₀ unsubstituted alkyl; (CH₂)₁₋₅CN, C₂₋₅ alkyl with one or morefluorine substitutions; C₅ alkenyl; and C₁₋₄ alkyl substituted withcycloalkyl. More particularly R² is selected from C₄₋₆ unsubstitutedn-alkyl, for example pentyl; (CH₂)₁₋₃CN, for example, (CH₂)CN or(CH₂)₃CN; C₃₋₄ alkyl with one or more fluorine substitutions, inparticular where the terminal carbon is fully saturated with fluorine,for example (CH₂)₂₋₃CF₃; and C₅ alkenyl, in particular, where there isonly one double bond, for example where the double bond is locatedbetween the fourth and fifth carbons (terminal alkenyl).

In particular embodiments, R³ represents halogen. More particularly, R³is selected from: chlorine and bromine. Most particularly, R³ representschlorine.

It is to be understood that the present invention includes anycombination of particular embodiments and covers all combinations ofparticular substituents described hereinabove.

Particular compounds of the present invention include:

-   (8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)acetonitrile,-   3-Butyl-8-chloro-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Bromo-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3,3,3-trifluoropropyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-1-propyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   3-Butyl-8-chloro-1-methyl-3,7-dihydro-1H-purine-2,6-dione,-   (3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile,-   8-Chloro-3-(2-cyclopropylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   4-(8-Chloro-1-methyl-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile,-   8-Chloro-1-ethyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   1-Methyl-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile,-   8-Chloro-3-propyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-propyl-3,7-dihydro-1H-purine-2,6-dione,-   3-Butyl-1-methyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile,-   8-Chloro-3-(4-penten-1-yl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-hexyl-3,7-dihydro-1H-purine-2,6-dione,-   4-(8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile,-   8-Chloro-3-hexyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione,-   3-Butyl-8-chloro-1-ethyl-3,7-dihydro-1H-purine-2,6-dione,-   [8-Chloro-3-(2-cyclopropylethyl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl]acetonitrile,-   (8-Chloro-2,6-dioxo-3-propyl-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile,-   8-Chloro-1-(4,4,4-trifluorobutyl)-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   2,2′-(8-Chloro-2,6-dioxo-6,7-dihydro-1H-purine-1,3(2H)-diyl)diacetonitrile,-   8-Chloro-1-methyl-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2-cyclohexylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   1,3-Dibutyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile,-   1,3-Dibutyl-8-iodo-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(4-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(6-methylheptyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-octyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-decyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclohexylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   (+/−)-8-Chloro-3-(3-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2-cyclopentylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclopropylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   (+/−)-8-Chloro-3-(2-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione,-   (+/−)-8-Chloro-3-(2-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclobutylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclopentylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3-cyclopropylpropyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2-cyclobutylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(4-fluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3-fluoropropyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(5-fluoropentyl)-3,7-dihydro-1H-purine-2,6-dione,-   4-(8-Chloro-1-methyl-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile,-   3-(3-Buten-1-yl)-8-chloro-3,7-dihydro-1H-purine-2,6-dione,-   6-(8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)-2,2-dimethylhexanenitrile,-   8-Chloro-3-(6-fluorohexyl)-3,7-dihydro-1H-purine-2,6-dione.

Throughout the present specification and the accompanying claims thewords “comprise” and “include” and variations such as “comprises”,“comprising”, “includes” and “including” are to be interpretedinclusively. That is, these words are intended to convey the possibleinclusion of other elements or integers not specifically recited, wherethe context allows.

As used herein, the terms “halogen” or “halo” refer to fluorine,chlorine, bromine and iodine.

As used herein, the term “alkyl” (when used as a group or as part of agroup) refers to a straight or branched hydrocarbon chain unlessspecified otherwise, containing the specified number of carbon atoms.For example, C₃-C₁₀alkyl means a straight or branched hydrocarbon chaincontaining at least 3 and at most 10 carbon atoms. Examples of alkyl asused herein include, but are not limited to methyl (Me), ethyl (Et),n-propyl and i-propyl. The term “n-alkyl” refers specifically to anun-branched hydrocarbon chain.

As used herein, the term “cycloalkyl” refers to a hydrocarbon ringcontaining between 3 and 6 carbon atoms, comprising no heteroatoms orconjugated double bonds. Examples of cycloalkyl as used herein include,but are not limited to cyclopropyl and cyclohexyl.

As used herein, the term “alkenyl” refers to a straight or branchedhydrocarbon chain containing the specified number of carbon atoms whichcontains one or more double bonds.

As used herein, where a group is referred to as being “substituted” withanother group or having “one or more substitutions” unless a particularposition for such a substitution is specified it is to be understoodthat a substitution may be present at any position in the group.

As used herein, the term “physiologically functional derivative” refersto any pharmaceutically acceptable derivative of a compound of thepresent invention, for example an amide thereof, and includes anypharmaceutically acceptable salt of a compound of formula (I), and anypharmaceutically acceptable solvate of a compound of formula (I) which,upon administration to a mammal, such as a human, is capable ofproviding (directly or indirectly) a compound of formula (I) or anactive metabolite or residue thereof. It will be appreciated by thoseskilled in the art that the compounds of formula (I) may be modified toprovide physiologically functional derivatives thereof at any of thefunctional groups in the compounds, and that the compounds of formula(I) may be so modified at more than one position.

As used herein, the term “pharmaceutically acceptable” used in relationto an ingredient (active ingredient or excipient) which may be includedin a pharmaceutical formulation for administration to a patient, refersto that ingredient being acceptable in the sense of being compatiblewith any other ingredients present in the pharmaceutical formulation andnot being deleterious to the recipient thereof.

As used herein, the term “solvate” refers to a complex of variablestoichiometry formed by a solute (in this invention, a compound offormula (I), a salt thereof or a physiologically functional derivativethereof) and a solvent. Such solvents for the purposes of the presentinvention may not interfere with the biological activity of the solute.The solvent used may be a pharmaceutically acceptable solvent. Examplesof suitable pharmaceutically acceptable solvents include water, ethanoland acetic acid. An example of a solvent that may be used is water, inwhich case the solvate may be referred to as a hydrate of the solute inquestion.

It will be appreciated that, for pharmaceutical use, the “salt orsolvate” referred to above will be a pharmaceutically acceptable salt orsolvate. However, other salts or solvates may find use, for example, inthe preparation of a compound of formula (I) or in the preparation of apharmaceutically acceptable salt or solvate thereof.

Pharmaceutically acceptable salts include those described by Berge,Bighley and Monkhouse, J. Pharm. Sci., 1977, 66, 1-19. Suitablepharmaceutically acceptable salts include alkali metal salts formed fromthe addition of alkali metal bases such as alkali metal hydroxides.Examples of suitable alkali metal salts are sodium salt or potassiumsalt. Other suitable pharmaceutically acceptable salts include alkalineearth metal salts such as calcium salt or magnesium salt, ammoniumsalts; or salts with organic bases such as ethanolamine,triethanolamine, ethylene diamine, triethylmine, choline and meglumine;or salts with amino acids such as arginine, lysine and histidine.

Compounds of formula (I) are of potential therapeutic benefit in thetreatment and amelioration of the symptoms of many diseases of lipidmetabolism including dyslipidaemia or hyperlipoproteinaemia such asdiabetic dyslipidaemia and mixed dyslipidaemia, heart failure,hypercholesteraemia, cardiovascular disease including atherosclerosis,arteriosclerosis, and hypertriglyceridaemia, type II diabetes mellitus,type I diabetes, insulin resistance, hyperlipidaemia, anorexia nervosa,obesity. As such, the compounds may also find favour as therapeutics forcoronary artery disease, thrombosis, angina, chronic renal failure,peripheral vascular disease and stroke.

Furthermore, it is also believed that the HM74 and HM74A receptors areinvolved in inflammation. Inflammation represents a group of vascular,cellular and neurological responses to trauma. Inflammation can becharacterised as the movement of inflammatory cells such as monocytes,neutrophils and granulocytes into the tissues. This is usuallyassociated with reduced endothelial barrier function and oedema into thetissues. Inflammation with regards to disease typically is referred toas chronic inflammation and can last up to a lifetime. Such chronicinflammation may manifest itself through disease symptoms. The aim ofanti-inflammatory therapy is therefore to reduce this chronicinflammation and allow for the physiological process of healing andtissue repair to progress.

Examples of inflammatory diseases or conditions for which the compoundsof the present invention may demonstrate utility include those of thejoint, particularly arthritis (e.g. rheumatoid arthritis,osteoarthritis, prosthetic joint failure), or the gastrointestinal tract(e.g. ulcerative colitis, Crohn's disease, and other inflammatory boweland gastrointestinal diseases, gastritis and mucosal inflammationresulting from infection, the enteropathy provoked by non-steroidalanti-inflammatory drugs), of the lung (e.g. adult respiratory distresssyndrome, asthma, cystic fibrosis, or chronic obstructive pulmonarydisease), of the heart (e.g. myocarditis), of nervous tissue (e.g.multiple sclerosis), of the pancreas, (e.g. inflammation associated withdiabetes melitus and complications thereof, of the kidney (e.g.glomerulonephritis), of the skin (e.g. dermatitis, psoriasis, eczema,urticaria, burn injury), of the eye (e.g. glaucoma) as well as oftransplanted organs (e.g. rejection) and multi-organ diseases (e.g.systemic lupus erythematosis, sepsis) and inflammatory sequelae of viralor bacterial infections and inflammatory conditions associated withatherosclerosis and following hypoxic or ischaemic insults (with orwithout reperfusion), for example in the brain or in ischaemic heartdisease.

In particular, the compounds of this invention are useful in thetreatment and prevention of inflammation, diabetes and cardiovasculardiseases or conditions including atherosclerosis, arteriosclerosis,hypertriglyceridemia, and mixed dyslipidaemia.

Nicotinic acid has a significant side effect profile, possibly becauseit is dosed at high level (gram quantities daily). The most common sideeffect is an intense cutaneous flushing. In certain embodiments of thepresent invention the compounds may exhibit reduced side effectscompared to nicotinic acid. HM74A has been identified as a high affinityreceptor for nicotinic acid whilst HM74 is a lower affinity receptor.The compounds of the present invention may find use as selective HM74Aagonists or partial agonists; in which case they will show greateraffinity for HM74A than for HM74.

The potential for compounds of formula (I) to activate HM74A may bedemonstrated, for example, using the following enzyme and in vitro wholecell assays:

In-Vitro Testing

For transient transfections, HEK293T cells (HEK293 cells stablyexpressing the SV40 large T-antigen) were maintained in DMEM containing10% foetal calf serum and 2 mM glutamine. Cells were seeded in 90 mmculture dishes and grown to 60-80% confluence (18-24 h) prior totransfection. Human HM74A (GenBank™ accession number AY148884) wassubcloned in to a mammalian expression vector (pcDNA3; Invitrogen) andtransfected using Lipofectamine reagent. For transfection, 9 μg of DNAwas mixed with 30 μl Lipofectamine in 0.6 ml of Opti-MEM (LifeTechnologies Inc.) and was incubated at room temperature for 30 minprior to the addition of 1.6 ml of Opti-MEM. Cells were exposed to theLipofectamine/DNA mixture for 5 h and 6 ml of 20% (v/v) foetal calfserum in DMEM was then added. Cells were harvested 48 h aftertransfection. Pertussis toxin treatment was carried out bysupplementation into media at 50 ngml⁻¹ for 16 h. All transienttransfection studies involved co-transfection of receptor together withthe G_(i/o) G protein, G_(o1)α.

For generation of stable cell lines the above method was used totransfect CHO-K1 cells seeded in six well dishes grown to 30%confluence. These cells were maintained in DMEM F-12 HAM mediacontaining 10% foetal calf serum and 2 mM glutamine. 48 hpost-transfection the media was supplemented with 400 μg/ml Geneticin(G418, Gibco) for selection of antibiotic resistant cells. Clonal CHO-K1cell lines stably expressing HM74A were confirmed by [³⁵S]-GTPγS bindingmeasurements, following the addition of nicotinic acid.

P2 Membrane Preparation

Plasma membrane-containing P2 particulate fractions were prepared fromcell pastes frozen at −80° C. after harvest. All procedures were carriedout at 4° C. Cell pellets were resuspended in 1 ml of 10 mM Tris-HCl and0.1 mM EDTA, pH 7.5 (buffer A) and by homogenisation for 20 s with aUltra Turrax followed by passage (5 times) through a 25-gauge needle.Cell lysates were centrifuged at 1,000 g for 10 min in a microcentrifugeto pellet the nuclei and unbroken cells and P2 particulate fractionswere recovered by microcentrifugation at 16,000 g for 30 min. P2particulate fractions were resuspended in buffer A and stored at −80° C.until required.

[³⁵S]-GTPγS Binding

assays were performed at room temperature in 384-well format based onmethods described previously, (Wieland, T. and Jakobs, K. H. (1994)Methods Enzymol. 237, 3-13). Briefly, the dilution of standard or testcompounds were prepared and added to a 384-well plate in a volume of 10μl. Membranes (HM74A or HM74) were diluted in assay buffer (20 mM HEPES,100 mM NaCl, 10 mM MgCl₂, pH7.4) supplemented with saponin (60 μg/ml),Leadseeker WGA beads (Amersham; 250 μg/well) and 10 μM GDP, so that the20 μl volume added to each well contains 5 μg of membranes. [³⁵S]-GTPγS(1170 Ci/mmol, Amersham) was diluted (1:1500) in assay buffer and 20 μladded to each well. Following the addition of the radioligand, theplates were sealed, pulse spun and incubated for 4 hours at roomtemperature. At the end of the incubation period the plates were read ona Leadseeker machine (VIEWLUX PLUS; Perkin-Elmer) to determine thelevels of specific binding.

In-Vivo Testing

HM74A agonists were tested in male Spague-Dawley rats (200-250 g) whichhad been fasted for at least 12 hours prior to the study. The compoundswere dosed intravenously (5 ml/kg) or by oral gavage (10 ml/kg). Bloodsamples (0.3 ml tail vein bleed) were taken pre-dose and at three timespost-dose (times ranging from 15 minutes to 8 hours post-dose). Eachblood sample was transferred to a heparin tube (Becton DickinsonMicrotainer, PST LH) and centrifuged (10,000 g for 5 minutes) to producea plasma sample. The plasma samples were assayed for levels ofnon-esterified fatty acids (NEFA) using a commercially available kit(Randox). Inhibition of plasma NEFA levels, relative to pre-dose levels,was used as a surrogate for HM74A agonist activity.

In order to determine whether HM74A compounds exhibited the flushingresponse associated with nicotinic acid they were dosed to anaesthetisedguinea-pigs. Male Dunkin Hartley guinea pigs (300-800 g) were fasted for12 hours prior to being anaesthetised with a mixture of Ketaminehydrochloride (Vetalar, 40 mg/kg i.m.), Xylazine (Rompun, 8 mg/kg i.m.)and sodium pentobarbitone (Sagatal, 30 mg/kg i.p.). Followinganaesthesia a tracheostomy was performed and the animals weremechanically ventilated with room air (10-12 mL/kg, 60 breaths/min). Ajugular vein, and a carotid artery, were cannulated for intravenousadministration of test compound and collection of blood respectively. Aninfra-red temperature probe (Extech Instruments) was placed 3-5 mm fromthe tip of the left ear. Temperature measurements were recorded everyminute from 5 minutes prior to test compound and up to 40 minutespost-administration of test compound. Data was automatically collectedon a Psion computer before being transferred for data analysis within anExcel spreadsheet. Prior to, and at frequent time points after, compoundadministration, blood samples (0.3 ml) were taken via the carotidarterial cannula and transferred to Microtainer (BD) tubes containinglithium heparin. The samples were mixed thoroughly on a blood roller andthen stored on ice prior to centrifugation at 1200 g for 5 minutes.

Nicotinic acid (10 mg/kg i.v.) produced a mean (±s.e.m.) increase in eartemperature equivalent to 10.42±1.44 (area under curve; arbitrary units;n=6). By comparison, the compound of Example 30 (10 mg/kg i.v.) produceda mean (±s.e.m.) increase in ear temperature equivalent to 1.52±0.39(area under curve; arbitrary units; n=6), a reduction of 85%.

Compounds according to Formula (I) have been synthesised (see syntheticexamples below) and tested in one or more of the assays discussed above.All of the exemplified compounds have a pEC50 of 4.9 (+/−0.3 log unit)or greater and an efficacy of 30% or greater. Some particular compoundsare exemplified below.

General Purification and Analytical Methods:

The mass spectra (MS) were recorded on a Fisons VG Platform massspectrometer using electrospray positive ionisation [(ES+ve to give MH⁺and M(NH₄)⁺ molecular ions] or electrospray negative ionisation [(ES−veto give (M-H)⁻ molecular ion] modes.

¹H NMR spectra were recorded using a Bruker DPX 400 MHz spectrometerusing tetramethylsilane as the external standard.

Biotage™ chromatography refers to purification carried out usingequipment sold by Dyax Corporation (either the Flash 40i or Flash 150i)and cartridges pre-packed with KPSil.

Mass directed autoprep refers to methods where the material was purifiedby high performance liquid chromatography on a HPLCABZ+ 5 μm column (5cm×10 mm i.d.) with 0.1% HCO₂H in water and 95% MeCN, 5% water (0.5%HCO₂H) utilising the following gradient elution conditions: 0-1.0minutes 5% B, 1.0-8.0 minutes 5→30% B, 8.0-8.9 minutes 30% B, 8.9-9.0minutes 30→95% B, 9.0-9.9 minutes 95% B, 9.9-10 minutes 95→0% B at aflow rate of 8 ml minutes⁻¹ (System 2). The Gilson 202-fractioncollector was triggered by a VG Platform Mass Spectrometer on detectingthe mass of interest.

Preparative h.p.l.c. refers to methods where the material was purifiedby high performance liquid chromatography on a HPLCABZ+ 5 μm column (10cm×21.2 mm i.d.) with 0.1% HCO₂H in water (A) and MeCN (0.5% HCO₂H) (B)utilising the generic gradient elution conditions expressed as “x to y”gradient with a gradient system as follows: 0-1.45 minutes x % B,1.45-20 minutes x→y % B, 20-24 minutes y→95% B, 24-30 minutes 95% B,32-34 minutes 95→x % B at a flow rate of 8 ml minutes⁻¹. The Gilson 233fraction collector was triggered by UV (254 nm).

SPE (solid phase extraction) refers to the use of cartridges sold byInternational Sorbent Technology Ltd.

Strata Phenyl SPE refers to the use of cartridges sold by Phenomenex.The compound was loaded onto a cartridge previously conditioned withMeCN and equilibrated with 5% MeCN in water. The compound was elutedwith 0.1% HCO₂H in water and MeCN (0.5% HCO₂H) in a suitable gradient ona Combiflash Optix 10.

As indicated above, compounds of Formula (I) may find use in human orveterinary medicine, in particular as activators of HM74A, in themanagement of dyslipidaemia and hyperlipoproteinaemia.

Thus, there is provided as a further aspect of the present invention acompound of formula (I) or a physiologically functional derivativethereof, for use in human or veterinary medicine, particularly in thetreatment of disorders of lipid metabolism including dyslipidaemia orhyperlipoproteinaemia such as diabetic dyslipidaemia and mixeddyslipidaemia, heart failure, hypercholesteraemia, cardiovasculardisease including atherosclerosis, arteriosclerosis, andhypertriglyceridaemia, type II diabetes mellitus, type I diabetes,insulin resistance, hyperlipidaemia, anorexia nervosa, obesity. As such,the compounds are also provided for use in the treatment of coronaryartery disease, thrombosis, angina, chronic renal failure, peripheralvascular disease and stroke.

There is provided as a further aspect of the present invention acompound of formula (I) or a physiologically functional derivativethereof, for use in the manufacture of a medicament for the treatment ofdisorders of lipid metabolism including dyslipidaemia orhyperlipoproteinaemia such as diabetic dyslipidaemia and mixeddyslipidaemia, heart failure, hypercholesteraemia, cardiovasculardisease including atherosclerosis, arteriosclerosis, andhypertriglyceridaemia, type II diabetes mellitus, type I diabetes,insulin resistance, hyperlipidaemia, anorexia nervosa, obesity. As such,the compounds are also provided for use in the treatment of coronaryartery disease, thrombosis, angina, chronic renal failure, peripheralvascular disease and stroke.

It will be appreciated that references herein to treatment extend toprophylaxis, prevention of recurrence and suppression of symptoms aswell as the treatment of established conditions.

According to another aspect of the invention, there is provided the useof a compound of formula (II)

and physiologically functional derivative thereof, wherein:R¹ is selected from: hydrogen and C₁₋₄ alkyl which may be optionallysubstituted with one or more groups selected from CN and CF₃;R² is selected from: C₂₋₁₀ unsubstituted alkyl, C₁₋₁₀ alkyl substitutedwith one or more groups selected from fluorine and CN, C₅ alkenyl,unbranched C₄ alkenyl, and C₁₋₄ alkyl substituted with cycloalkyl;and R³ is selected from halogen and CN;in the manufacture of a medicament for the treatment of disorders oflipid metabolism including dyslipidaemia or hyperlipoproteinaemia. Inparticular, the use is provided of a compound of Formula (II) in themanufacture of a medicament for the treatment of diabetic dyslipidaemiaor mixed dyslipidaemia, heart failure, hypercholesteraemia, type IIdiabetes mellitus, type I diabetes, insulin resistance, hyperlipidaemia,anorexia nervosa, obesity, coronary artery disease, thrombosis, angina,chronic renal failure, stroke and cardiovascular disease includingatherosclerosis, arteriosclerosis, and hypertriglyceridaemia.

In one embodiment of the invention, there is provided a compound offormula (II) for use in the treatment of disorders of lipid metabolismincluding dyslipidaemia or hyperlipoproteinaemia. In particular, the useis provided of a compound of Formula (II) in the manufacture of amedicament for the treatment of diabetic dyslipidaemia or mixeddyslipidaemia, heart failure, hypercholesteraemia, type II diabetesmellitus, type I diabetes, insulin resistance, hyperlipidaemia, anorexianervosa, obesity, coronary artery disease, thrombosis, angina, chronicrenal failure, stroke and cardiovascular disease includingatherosclerosis, arteriosclerosis, and hypertriglyceridaemia.

In particular embodiments, R¹ is selected from: hydrogen, C₁₋₄ alkyl,CH₂CN and (CH₂)₃CF₃. In more particular embodiments R¹ is selected from:hydrogen and methyl.

In certain embodiments R² is selected from: C₃₋₁₀ unsubstituted alkyl,C₁₋₁₀ alkyl substituted with one or more groups selected from fluorineand CN, C₅ alkenyl, unbranched C₄ alkenyl, and C₁₋₄ alkyl substitutedwith cycloalkyl. Particularly, R² is selected from: C₃₋₁₀ unsubstitutedalkyl, C₁₋₆alkyl with one or more CN substitutions, C₁₋₁₀ alkyl with oneor more fluorine substitutions, C₅ alkenyl, unbranched C₄ alkenyl, andC₁₋₄ alkyl substituted with cycloalkyl. More particularly R² is selectedfrom: C₃₋₁₀ unsubstituted alkyl; (CH₂)₁₋₅CN, C₂₋₅ alkyl with one or morefluorine substitutions; C₅ alkenyl; and C₁₋₄ alkyl substituted withcycloalkyl. Most particularly R² is selected from C₄₋₆ unsubstitutedn-alkyl, for example pentyl; (CH₂)₁₋₃CN, for example, (CH₂)CN or(CH₂)₃CN; C₃₋₄ alkyl with one or more fluorine substitutions, inparticular where the terminal carbon is fully saturated with fluorine,for example (CH₂)₂₋₃CF₃; and C₅ alkenyl, in particular, where there isonly one double bond, for example where the double bond is locatedbetween the fourth and fifth carbons (terminal alkenyl).

In particular embodiments, R³ represents halogen. More particularly, R³is selected from chlorine and bromine. Most particularly, R³ representschlorine.

Particular compounds for use in the treatment of, or in the manufactureof a medicament for the treatment of disorders of lipid metabolismincluding dislipidaemia or hyperlipoproteinaemia include:

-   (8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)acetonitrile,-   3-Butyl-8-chloro-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Bromo-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3,3,3-trifluoropropyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-1-propyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   3-Butyl-8-chloro-1-methyl-3,7-dihydro-1H-purine-2,6-dione,-   (3-Butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile,-   8-Chloro-3-(2-cyclopropylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   4-(8-Chloro-1-methyl-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile,-   8-Chloro-1-ethyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   1-Methyl-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile,-   8-Chloro-3-propyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-propyl-3,7-dihydro-1H-purine-2,6-dione,-   3-Butyl-1-methyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile,-   8-Chloro-3-(4-penten-1-yl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-hexyl-3,7-dihydro-1H-purine-2,6-dione,-   4-(8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile,-   8-Chloro-3-hexyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione,-   3-Butyl-8-chloro-1-ethyl-3,7-dihydro-1H-purine-2,6-dione,-   [8-Chloro-3-(2-cyclopropylethyl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl]acetonitrile,-   (8-Chloro-2,6-dioxo-3-propyl-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile,-   8-Chloro-1-(4,4,4-trifluorobutyl)-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione,-   2,2′-(8-Chloro-2,6-dioxo-6,7-dihydro-1H-purine-1,3(2H)-diyl)diacetonitrile,-   8-Chloro-1-methyl-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2-cyclohexylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   1,3-Dibutyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile,-   1,3-Dibutyl-8-iodo-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(4-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(6-methylheptyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-octyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-decyl-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclohexylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   (+/−)-8-Chloro-3-(3-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2-cyclopentylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclopropylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   (+/−)-8-Chloro-3-(2-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione,-   (+/−)-8-Chloro-3-(2-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclobutylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(cyclopentylmethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3-cyclopropylpropyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(2-cyclobutylethyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(4-fluorobutyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(3-fluoropropyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-Chloro-3-(5-fluoropentyl)-3,7-dihydro-1H-purine-2,6-dione,-   4-(8-Chloro-1-methyl-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile,-   3-(3-Buten-1-yl)-8-chloro-3,7-dihydro-1H-purine-2,6-dione,-   6-(8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)-2,2-dimethylhexanenitrile,-   8-Chloro-3-(6-fluorohexyl)-3,7-dihydro-1H-purine-2,6-dione,-   8-chloro-3-ethyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione.

It is to be understood that this aspect of the present inventionincludes any combination of particular embodiments and covers allcombinations of particular substituents described herein above forcompounds of Formula (II).

Additionally, the present invention provides the use of a compound offormula (I) or a physiologically functional derivative thereof, in themanufacture of a medicament for the treatment of inflammatory diseasesor conditions of the joint, particularly arthritis (e.g. rheumatoidarthritis, osteoarthritis, prosthetic joint failure), or of thegastrointestinal tract (e.g. ulcerative colitis, Crohn's disease, andother inflammatory bowel and gastrointestinal diseases, gastritis andmucosal inflammation resulting from infection, the enteropathy provokedby non-steroidal anti-inflammatory drugs), of the lung (e.g. adultrespiratory distress syndrome, asthma, cystic fibrosis, or chronicobstructive pulmonary disease), of the heart (e.g. myocarditis), ofnervous tissue (e.g. multiple sclerosis), of the pancreas, (e.g.inflammation associated with diabetes melitus and complications thereof,of the kidney (e.g. glomerulonephritis), of the skin (e.g. dermatitis,psoriasis, eczema, urticaria, burn injury), of the eye (e.g. glaucoma)as well as of transplanted organs (e.g. rejection) and multi-organdiseases (e.g. systemic lupus erythematosis, sepsis) and inflammatorysequelae of viral or bacterial infections and inflammatory conditionsassociated with atherosclerosis and following hypoxic or ischaemicinsults (with or without reperfusion), for example in the brain or inischaemic heart disease.

In a further or alternative aspect there is provided a method for thetreatment of a human or animal subject with a condition whereunder-activation of the HM74A receptor contributes to the condition orwhere activation of the receptor will be beneficial, which methodcomprises administering to said human or animal subject an effectiveamount of a compound of formula (I) or a physiologically acceptable saltor solvate thereof.

Again, it is to be understood that this aspect of the present inventionincludes any combination of particular embodiments and covers allcombinations of particular substituents described herein above forcompounds of Formula (I).

More particularly, the present invention provides a method for thetreatment of disorders of lipid metabolism including dyslipidaemia orhyperlipoproteinaemia such as diabetic dyslipidaemia and mixeddyslipidaemia, heart failure, hypercholesteraemia, cardiovasculardisease including atherosclerosis, arteriosclerosis, andhypertriglyceridaemia, type II diabetes mellitus, type I diabetes,insulin resistance, hyperlipidaemia, anorexia nervosa, obesity, whichmethod comprises administering to said human or animal subject aneffective amount of a compound of formula (I) or a physiologicallyacceptable salt or solvate thereof. As such, these compounds may alsofind favour in methods for the treatment of coronary artery disease,thrombosis, angina, chronic renal failure, peripheral vascular diseaseand stroke, which methods comprise administering to said human or animalsubject an effective amount of a compound of formula (I).

The amount of a HM74A modulator which is required to achieve the desiredbiological effect will, of course, depend on a number of factors, forexample, the mode of administration and the precise clinical conditionof the recipient. In general, the daily dose will be in the range of 0.1mg-1 g/kg, typically 0.1-100 mg/kg. An intravenous dose may, forexample, be in the range of 0.01 mg to 0.1 g/kg, typically 0.01 mg to 10mg/kg, which may conveniently be administered as an infusion of from 0.1μg to 1 mg, per minute. Infusion fluids suitable for this purpose maycontain, for example, from 0.01 μg to 0.1 mg, per milliliter. Unit dosesmay contain, for example, from 0.01 μg to 1 g of a HM74A modulator. Thusampoules for injection may contain, for example, from 0.01 μg to 0.1 gand orally administrable unit dose formulations, such as tablets orcapsules, may contain, for example, from 0.1 mg to 1 g. No toxicologicaleffects are indicated/expected when a compound of the invention isadministered in the above mentioned dosage range.

A compound of the present invention may be employed as the compound perse in the treatment of a disease where under-activation of the HM74Areceptor contributes to the disease or where activation of the receptorwill be beneficial, an example of this is where a compound of thepresent invention is presented with an acceptable carrier in the form ofa pharmaceutical formulation. The carrier must, of course, be acceptablein the sense of being compatible with the other ingredients of theformulation and must not be deleterious to the recipient. The carriermay be a solid or a liquid, or both, and may be formulated with theHM74A modulator as a unit-dose formulation, for example, a tablet, whichmay contain from 0.05% to 95% by weight of the HM74A modulator.

The formulations include those suitable for oral, rectal, topical,buccal (e.g. sub-lingual) and parenteral (e.g. subcutaneous,intramuscular, intradermal or intravenous) administration.

There is also provided according to the invention a process forpreparation of such a pharmaceutical composition which comprises mixingthe ingredients.

Formulations suitable for oral administration may be presented indiscrete units, such as capsules, cachets, lozenges or tablets, eachcontaining a predetermined amount of a HM74A modulator; as a powder orgranules; as a solution or a suspension in an aqueous or non-aqueousliquid; or as an oil-in-water or water-in-oil emulsion. In general, theformulations are prepared by uniformly and intimately admixing theactive HM74A modulator with a liquid or finely divided solid carrier, orboth, and then, if necessary, shaping the product. For example, a tabletmay be prepared by compressing or moulding a powder or granules of theHM74A modulator optionally with one or more accessory ingredients.Compressed tablets may be prepared by compressing, in a suitablemachine, the compound in a free-flowing form, such as a powder orgranules optionally mixed with a binder, lubricant, inert diluent and/orsurface active/dispersing agent(s). Moulded tablets may be made bymoulding, in a suitable machine, the powdered compound moistened with aninert liquid diluent.

Tablets and capsules for oral administration may contain conventionalexcipients such as binding agents, for example syrup, acacia, gelatin,sorbitol, tragacanth, mucilage of starch or polyvinyl pyrrolidone;fillers, for example, lactose, microcrystalline cellulose, sugar,maize-starch, calcium phosphate or sorbitol; lubricants, for example,magnesium stearate, stearic acid, talc, polyethylene glycol or silica;disintegrants, for example, potato starch, croscarmellose sodium orsodium starch glycollate; or wetting agents such as sodium laurylsulphate. The tablets may be coated according to methods well known inthe art. Oral liquid preparations may be in the form of, for example,aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, ormay be presented as a dry product for constitution with water or othersuitable vehicle before use. Such liquid preparations may containconventional additives such as suspending agents, for example, sorbitolsyrup, methyl cellulose, glucose/sugar syrup, gelatin, hydroxymethylcellulose, carboxymethyl cellulose, aluminium stearate gel orhydrogenated edible fats; emulsifying agents, for example, lecithin,sorbitan mono-oleate or acacia; non-aqueous vehicles (which may includeedible oils), for example almond oil, fractionated coconut oil, oilyesters, propylene glycol or ethyl alcohol; or preservatives, forexample, methyl or propyl p-hydroxybenzoates or sorbic acid. Thepreparations may also contain buffer salts, flavouring, colouring and/orsweetening agents (e.g. mannitol) as appropriate.

Formulations suitable for buccal (sub-lingual) administration includelozenges comprising a HM74A modulator in a flavoured base, usuallysucrose and acacia or tragacanth, and pastilles comprising the HM74Amodulator in an inert base such as gelatin and glycerin or sucrose andacacia.

Formulations of the present invention suitable for parenteraladministration conveniently comprise sterile aqueous preparations of anHM74A modulator, the formulation may be isotonic with the blood of theintended recipient. These preparations could be administeredintravenously, although administration may also be effected by means ofsubcutaneous, intramuscular, or intradermal injection. Such preparationsmay conveniently be prepared by admixing the HM74A modulator with waterand rendering the resulting solution sterile and isotonic with theblood. Injectable compositions according to the invention will generallycontain from 0.1 to 5% w/w of the HM74A modulator.

Thus, formulations of the present invention suitable for parenteraladministration comprising a compound according to the invention may beformulated for parenteral administration by bolus injection orcontinuous infusion and may be presented in unit dose form, for instanceas ampoules, vials, small volume infusions or pre-filled syringes, or inmulti-dose containers with an added preservative. The compositions maytake such forms as solutions, suspensions, or emulsions in aqueous ornon-aqueous vehicles, and may contain formulatory agents such asanti-oxidants, buffers, antimicrobial agents and/or toxicity adjustingagents. Alternatively, the active ingredient may be in powder form forconstitution with a suitable vehicle, e.g. sterile, pyrogen-free water,before use. The dry solid presentation may be prepared by filling asterile powder aseptically into individual sterile containers or byfilling a sterile solution aseptically into each container andfreeze-drying.

Formulations suitable for rectal administration may be presented asunit-dose suppositories. These may be prepared by admixing a HM74Amodulator with one or more conventional solid carriers, for example,cocoa butter or glycerides and then shaping the resulting mixture.

Formulations suitable for topical application to the skin may take theform of an ointment, cream, lotion, paste, gel, spray, aerosol, or oil.Carriers which may be used include vaseline, lanolin, polyethyleneglycols, alcohols, and combinations of two or more thereof. The HM74Amodulator is generally present at a concentration of from 0.1 to 15% w/wof the composition, for example, from 0.5 to 2%.

By topical administration as used herein, we include administration byinsufflation and inhalation. Examples of various types of preparationfor topical administration include ointments, creams, lotions, powders,pessaries, sprays, aerosols, capsules or cartridges for use in aninhaler or insufflator or drops (e.g. eye or nose drops).

Ointments and creams may, for example, be formulated with an aqueous oroily base with the addition of suitable thickening and/or gelling agentsand/or solvents. Such bases may thus, for example, include water and/oran oil such as liquid paraffin or a vegetable oil such as arachis oil orcastor oil or a solvent such as a polyethylene glycol. Thickening agentswhich may be used include soft paraffin, aluminium stearate, cetostearylalcohol, polyethylene glycols, microcrystalline wax and beeswax.

Lotions may be formulated with an aqueous or oily base and will ingeneral also contain one or more emulsifying agents, stabilising agents,dispersing agents, suspending agents or thickening agents.

Powders for external application may be formed with the aid of anysuitable powder base, for example, talc, lactose or starch. Drops may beformulated with an aqueous or non-aqueous base also comprising one ormore dispersing agents, solubilising agents or suspending agents.

Spray compositions may be formulated, for example, as aqueous solutionsor suspensions or as aerosols delivered from pressurised packs, with theuse of a suitable propellant, e.g. dichlorodifluoromethane,trichlorofluoromethane, dichlorotetrafluoroethane,1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,2-tetrafluorethane, carbondioxide or other suitable gas.

Capsules and cartridges for use in an inhaler or insufflator, of forexample gelatin, may be formulated containing a powder mix of a compoundof the invention and a suitable powder base such as lactose or starch.

The pharmaceutical compositions according to the invention may also beused in combination with other therapeutic agents, for example incombination with other classes of dyslipidaemic drugs (e.g. statins,fibrates, bile-acid binding resins or nicotinic acid).

The compounds of the instant invention may be used in combination withone or more other therapeutic agents for example in combination withother classes of dyslipidaemic drugs e.g.3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) orfibrates or bile acid binding resins or nicotinic acid. The inventionthus provides, in a further aspect, the use of such a combination in thetreatment of diseases where under-activation of the HM74A receptorcontributes to the disease or where activation of the receptor will bebeneficial and the use of a compound of formula (I) or (II) or apharmaceutically acceptable salt, solvate or physiologically functionalderivative thereof in the manufacture of a medicament for thecombination therapy of disorders of lipid metabolism includingdyslipidaemia or hyperlipoproteinaemia such as diabetic dyslipidaemiaand mixed dyslipidaemia, heart failure, hypercholesteraemia,cardiovascular disease including atherosclerosis, arteriosclerosis, andhypertriglyceridaemia, type II diabetes mellitus, type I diabetes,insulin resistance, hyperlipidaemia, anorexia nervosa or obesity.

When the compounds of the present invention are used in combination withother therapeutic agents, the compounds may be administered eithersequentially or simultaneously by any convenient route.

The combinations referred to above may conveniently be presented for usein the form of a pharmaceutical formulation and thus pharmaceuticalformulations comprising a combination as defined above optimallytogether with a pharmaceutically acceptable carrier or excipientcomprise a further aspect of the invention. The individual components ofsuch combinations may be administered either sequentially orsimultaneously in separate or combined pharmaceutical formulations.

When combined in the same formulation it will be appreciated that thetwo components must be stable and compatible with each other and theother components of the formulation and may be formulated foradministration. When formulated separately they may be provided in anyconvenient formulation, conveniently in such a manner as are known forsuch compounds in the art.

When in combination with a second therapeutic agent active against thesame disease, the dose of each component may differ from that when thecompound is used alone. Appropriate doses will be readily appreciated bythose skilled in the art.

The invention thus provides, in a further aspect, a combinationcomprising a compound of formula (I) or (II) or a physiologicallyacceptable salt or solvate thereof together with another therapeuticallyactive agent.

The combination referred to above may conveniently be presented for usein the form of a pharmaceutical formulation and thus pharmaceuticalformulations comprising a combination as defined above together with apharmaceutically acceptable carrier thereof represent a further aspectof the invention.

The compounds of the present invention have useful duration of action.

The compounds of the present invention and salts and solvates thereofmay be prepared by the methodology described hereinafter, constituting afurther aspect of this invention.

Process A:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R¹ is H or is the same as R² and R³ is Cl,comprises:

Process B:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R³ is CN comprises steps (i) and (ii) ofProcess A followed by:

Process C:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R³ is Cl or Br comprises steps (i) to (iv)of Process B followed by:

Process D:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R³ is CN comprises steps (i) to (iv) ofProcess B followed by:

Process E:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R³ is Cl comprises:

Process F:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R¹ differs from R² and R³ is Cl comprisessteps (i) to (iv) of Process A followed by:

Process G:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R¹ differs from R² and R³ is Cl comprisessteps (i) to (v) of Process F (where R² from process F is specificallySEM or MEM) followed by:

Process H:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R³ is Cl, Br, I or F comprises steps (i) to(iv) of Process B followed by:

Process I:

A process according to the invention for preparing a compound of formula(I) or formula (II) in which R¹ is H or alkyl, R² is alkyl and R³ is Clcomprises:

Where desired or necessary, as a final stage in any of the abovesynthetic processes, a resultant compound of formula (I) or (II) can beconverted into a physiologically acceptable salt form or vice versa orconverting one salt form into another physiologically acceptable saltform.

ABBREVIATIONS

-   -   THF Tetrahydrofuran    -   Ac Acetyl    -   DCM Dichloromethane    -   DMEM Dulbecco's Modified Eagle's Medium    -   HEPES 4-(2-Hydroxyethyl)piperazine-1-ethanesulphonic acid    -   DMSO Dimethylsulphoxide    -   NBS N-bromosuccinimide    -   NCS N-chlorosuccinimide    -   NIS N-iodosuccinimide    -   DMF Dimethylformamide    -   LiHMDS Lithium hexamethyldisilylamide    -   DBAD Dibenzylazodicarboxylate    -   DIPEA Diisopropylethylamine    -   PyBOP Benzotriazo-1-yloxytripyrrolidinophosphonium        hexafluorophosphate    -   MEM Methoxyethyloxymethyl    -   SEM 2-(trimethylsilyl)ethoxymethyl    -   TFA Trifluoroacetic acid    -   RT room temperature    -   Heat        The following non-limiting examples illustrate the present        invention:

SYNTHETIC EXAMPLES Example 18-Chloro-3-(4-penten-1-yl)-3,7-dihydro-1H-purine-2,6-dione

a) 2-amino-7-(2-propen-1-yl)-1,7-dihydro-6H-purin-6-one

A mixture of guanosine (20 g, 0.071 mol), allyl bromide (14.7 ml, 0.169mol) and anhydrous DMSO (100 ml) was stirred at rt, under nitrogen, for18 hours. Concentrated HCl (50 ml of 37%) was added in one portion andthe mixture stirred for 45 minutes then poured into MeOH (600 ml). Themethanolic solution was neutralised with 2M NaOH(aq) solution and theresulting white precipitate collected by filtration. The white solid wasdried under vacuum at 50° C. for 18 hours to afford the title compound(16 g crude, 119%). m/z 192.2 [MH⁺].

b) 7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

A mixture of 2-amino-7-(2-propen-1-yl)-1,7-dihydro-6H-purin-6-one (40 g,0.209 mol) in AcOH (900 ml) and water (100 ml) was heated at 55° C.Sodium nitrite (57.74 g, 0.837 mol) in water (100 ml) was addeddropwise. Care; toxic fumes. After the addition was complete(approximately 25 minutes) the reaction mixture was allowed to cool toambient temperature and then concentrated to approximately ⅓ of itsoriginal volume. Water (500 ml) was added and the resulting precipitatecollected by filtration. The residue was washed with water then dried at50° C. over P₂O₅ and under vacuum for 2 hours to give the title compound(17.20 g). The aqueous fraction was concentrated and water added (100ml). Again the resulting solid was filtered and dried. This gave more ofthe title compound (2.31 g). Combined product (19.52 g, 49%). m/z 193.2[MH⁺].

c) 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of 7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione)(10.52 g, 54.7 mmol) in anhydrous DMF (60 ml) was added NCS (8.04 g,60.2 mmol). The reaction mixture was left to stir under nitrogen at 20°C. for 6 hours. The reaction mixture was concentrated in vacuo to givean amber oil. MeOH was added and left to stand for 18 hours. Theresulting residue was filtered and dried under vacuum to give the titlecompound (7.69 g, 62%). m/z 227.2 [MH⁺].

d) 8-Chloro-3-(4-penten-1-yl)-3,7-dihydro-1H-purine-2,6-dione

8-Chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (0.10 g, 0.44mmol) was dissolved in DMF (1.5 ml) containing sodium carbonate (0.12 g,0.49 mmol) and 5-bromopentene (0.07 g, 0.49 mmol) and the mixturestirred for 18 h. On completion of alkylation, morpholine (0.5 ml) andtetrakis(triphenylphosphine) palladium (0) (0.08 g, 0.07 mmol) wereadded and stirring continued for 3.5 h. The reaction was diluted withethyl acetate (10 ml) washed sequentially with 2N hydrochloric acid (2×5ml) and brine (3×5 ml) and the organic isolated, dried (MgSO₄) andconcentrated. The crude product was suspended in methanol (2 ml) andpurified on an aminopropyl SPE (5 g) eluting with methanol first then 5%acetic acid in methanol to elute the title compound which was isolatedas a white solid after concentration (0.039 g, 35%). NMR; (400 MHz,d⁶-DMSO) 1.75 (m, 2H), 2.05 (m, 2H), 3.85 (t, 2H, J=7 Hz), 4.95 (m, 1H),5.05 (m, 1H), 5.8 (m, 1H), 11.1 (br s, 1H), one exchangeable proton notobserved to δ_(H) 13; m/z 255 [MH⁺]

Example 2 8-Chloro-3-hexyl-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 1 using hexyl iodide, to affordthe title compound. NMR; δ_(H) (400 MHz, d⁶-DMSO) 0.85 (t, 3H, J=7 Hz),1.25 (br s, 6H), 1.6 (m, 2H), 3.85 (t, 2H, J=8 Hz), 11.2 (br. s, 1H),one exchangeable proton not observed to δ_(H) 13; m/z 271 [MH⁺]

Examples 3 and 4(8-chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)acetonitrile and2,2′-(8-chloro-2,6-dioxo-6,7-dihydro-1H-purine-1,3(2H)-diyl)diacetonitrile

a)[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-1,2,6,7-tetrahydro-3H-purin-3-yl]acetonitrileand2,2′-[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-6,7-dihydro-1H-purine-1,3(2H)-diyl]diacetonitrile

A solution of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(0.445 g, 2.0 mmol) in DMF (8 ml) was treated with sodium carbonate(0.18 g, 1.7 mmol) and bromoacetonitrile (0.1 ml, 1.4 mmol). The stirredmixture was heated at 70° C. for 3 hours then cooled to 50° C. andtreated with further bromoacetonitrile (0.06 ml, 0.8 mmol). The mixturewas maintained at 50° C. for a further 2 hours and then cooled toambient temperature and evaporated to dryness. The residue was treatedwith 1M aqueous hydrochloric acid (20 ml) and extracted with ethylacetate (2×50 ml). The organic fractions were combined, dried overmagnesium sulfate, filtered and evaporated. The residue was dissolved indichloromethane (2 ml), after 20 minutes, the resulting precipitatedsolid (unreacted8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione was filteredoff and washed with further dichloromethane). The filtrate wasconcentrated in vacuo and subjected to flash chromatography using ethylacetate/cyclohexane as eluant in a gradient elution from 1:3 to 4:1. Toafford the two title compounds:

-   [8-chloro-2,6-dioxo-7-(2-propen-1-yl)-1,2,6,7-tetrahydro-3H-purin-3-yl]acetonitrile

White solid (0.084 g, 16%); m/z 266 [MH⁺].

-   2,2′-[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-6,7-dihydro-1H-purine-1,3(2H)-diyl]diacetonitrile

White solid (0.195 g, 32%); m/z 305 [MH⁺].

b) (8-chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)acetonitrile

A solution of[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-1,2,6,7-tetrahydro-3H-purin-3-yl]acetonitrile(0.084 g, 0.32 mmol) in THF (5 ml) was degassed by the successiveapplication of vacuum and nitrogen pressure to the reaction mixture. Thesolution was subsequently treated with morpholine (0.3 ml, 3.4 mmol) andtetrakis(triphenylphosphine)palladium(0) (0.03 g, 0.03 mmol). After 2hours, the mixture was treated with 2M aqueous hydrochloric acid (3 ml)and chloroform (5 ml). The mixture was separated and the organic phaseevaporated. The product was purified from the residue usingmass-directed HPLC, to afford the title compound as a white solid (0.018g, 25%). NMR δ_(H) (400 MHz, d⁶-DMSO) 4.95 (s, 2H), 11.49 (s, 1H), 14.63(br. s, 1H); m/z 226 [MH⁺].

c)2,2′-(8-chloro-2,6-dioxo-6,7-dihydro-1H-purine-1,3(2H)-diyl)diacetonitrile

The title compound was prepared from2,2′-[8-chloro-2,6-dioxo-7-(2-propen-1-yl)-6,7-dihydro-1H-purine-1,3(2H)-diyl]diacetonitrileusing the conditions described for the synthesis of(8-chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)acetonitrile.

To afford the title compound as a white solid 0.06 g (4%); NMR δ_(H)(400 MHz, d⁶-DMSO) 4.88 (s, 2H), 5.06 (s, 2H), NH not observed to δ_(H)14; m/z 282 [MNH₄ ⁺].

Example 58-chloro-3-(3,3,3-trifluoropropyl)-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 3 using3-bromo-1,1,1-trifluoropropane as alkylating agent to afford titlecompound.

NMR δ_(H) (400 MHz, d⁶-DMSO) 2.64-2.76 (m, 2H), 4.12 (t, 2H, J=7 Hz),11.30 (s, 1H), 14.46 (br. s, 1H); m/z 283 [MH⁺]

Example 68-chloro-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 3 using2-bromo-1,1,1-trifluoroethane as the alkylating agent and sodiumbicarbonate as base to afford title compound.

δ_(H) (400 MHz, d⁴-MeOD) 4.68 (q, 2H, J=8.5 Hz); m/z 267.1 [M-H]⁻

Example 7 and 88-chloro-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione and8-chloro-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dioneand8-chloro-7-(2-propen-1-yl)-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.5 g, 6.64mmol), sodium carbonate (844 mg, 7.9 mmol) and4-bromo-1,1,1-trifluorobutane (1.39 g, 7.3 mmol) were stirred indimethylformamide (25 ml, dry) for seven days. The reaction mixture waspartitioned between ethyl acetate and water. The organic phase wasseparated and washed with hydrochloric acid (2N), brine, dried (MgSO₄)and then evaporated to dryness. The crude product was triturated withether and the solid collected by filtration to afford8-chloro-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dioneas a white solid (1.23 g, 57%). m/z 337 [MH⁺].

The reduced filtrate was chromatographed on silica, SPE column (20 g).Elution with cyclohexane:ethylacetate (10:1 to 2:1) afforded8-chloro-7-(2-propen-1-yl)-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dioneas a syrup (480 mg, 16%). m/z 447 [MH⁺].

b) 8-chloro-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

8-chloro-7-(2-propen-1-yl)-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione(84 mg, 0.25 mmol) and morpholine (220 ul, 2.5 mmol) were degassed withnitrogen in tetrahydrofuran (3 ml) and thentetrakis(triphenylphosphine)palladium(0) (29 mg, 0.025 mmol) was addedand the reaction stirred at room temperature overnight. The whiteprecipitate was collected by filtration and washed with tetrahyrofuranand ether to afford the morpholine salt of the title compound (59 mg).This was treated with 2N HCl and methanol and the solvents evaporated todryness before re-dissolving in DMSO/MeOH and purifying by preparativeHPLC using a 10 to 40% gradient to give the title compound (11 mg,14.9%). NMR δ_(H) (400 MHz, d⁴-MeOD) 1.92-2.03 (m, 2H), 2.19-2.33 (m,2H), 4.06 (t, 2H, J=7 Hz); m/z 297 [MH⁺].

c)8-chloro-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

8-chloro-7-(2-propen-1-yl)-1,3-bis(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione(478 mg, 1.1 mmol) and morpholine (937 ul, 11 mmol) were degassed withnitrogen in tetrahydrofuran (10 ml) and thentetrakis(triphenylphosphine)palladium(0) (123 mg, 0.11 mmol) was addedand the reaction stirred at room temperature overnight. The reactionmixture was partitioned between dichloromethane and hydrochloric acid2N. The organic phase was separated and reduced to give the crudeproduct. This was purified by aminopropyl SPE (5 g) followed byre-crystallisation from acetonitrile to afford the title compound (75.5mg, 16.9%). NMR. δ_(H) (400 MHz, CDCl₃) 1.96-2.13 (m, 4H), 2.15-2.29 (m,4H), 4.15-4.23 (m, 4H), 12.94 (br. s, 1H); m/z 407 [MH⁺].

Example 98-chloro-3-(2-cyclopropylethyl)-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-3-(2-cyclopropylethyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.5 g, 6.64mmol), sodium carbonate (844 mg, 7.9 mmol) and 2-cyclopropylethylmethanesulfonate (1.19 g, 7.3 mmol) were stirred in dimethylformamide(25 ml, dry) for two days at 80° C. The reaction mixture was partitionedbetween ethyl acetate and water. The organic phase was separated andwashed with hydrochloric acid (2N), brine, dried (MgSO₄) and thenevaporated to dryness. The crude product was triturated with ether andthe solid collected by filtration to afford the title compound as awhite solid (0.96 g, 49%). m/z 295 [MH⁺].

b) 8-chloro-3-(2-cyclopropylethyl)-3,7-dihydro-1H-purine-2,6-dione

8-chloro-3-(2-cyclopropylethyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(74 mg, 0.25 mmol) and morpholine (220 ul, 2.5 mmol) were degassed withnitrogen in tetrahydrofuran (3 ml) and thentetrakis(triphenylphosphine)palladium(0) (29 mg, 0.025 mmol) was addedand the reaction stirred at room temperature overnight. The whiteprecipitate was collected by filtration and washed with tetrahyrofuranand ether to afford the morpholine salt of the title compound (52 mg).This was treated with 2N HCl and methanol and the solvents evaporated todryness before re-dissolving in DMSO/MeOH and purifying by preparativeHPLC using a 10 to 40% gradient to give the title compound (22 mg,34.6%). NMR δ_(H) (400 MHz, d⁴-MeOD) 0.00-0.05 (m, 2H), 0.37-0.43 (m,2H), 0.67-0.77 (m, 1H), 1.61 (q, 2H, J=7 Hz), 4.06-4.11 (m, 2H); m/z 255[MH⁺].

Example 10 3-butyl-8-chloro-3,7-dihydro-1H-purine-2,6-dione

a) 3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of3-butyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (3.34 g, 13.4mmol) in anhydrous DMF (19 ml) was added NCS (1.97 g, 14.8 mmol) andleft to stir at rt under nitrogen for 22 hours. The mixture wasconcentrated in vacuo to give a yellow solid which was filtered andwashed with methanol. The filtrate was concentrated and the processrepeated. On the final wash the filtrate was purified by SPE (Si, 20 g)cartridge eluting with 1:1; EtOAc:cyclohexane. The combined solids weredried under vacuum to afford the title compound (2.42 g, 64%); m/z 283.3[MH⁺]

b) 3-butyl-8-chloro-3,7-dihydro-1H-purine-2,6-dione

A solution of3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100mg, 0.35 mmol) in anhydrous THF (4 ml) and anhydrous DMSO (0.4 ml) wastreated with Pd(PPh₃)₄ (61 mg, 0.053 mmol). The mixture was degassedunder gentle vacuum, morpholine (308 uL, 3.5 mmol) was added, and leftto stir at rt under nitrogen for 4 hours. The yellow solution waspartitioned between 2M HCl(aq) and EtOAc. The organic layer wasseparated, washed with brine, dried (MgSO₄) and concentrated. Theresidue was taken up in MeOH and passed down an amino-propyl SPE (5 g),eluting with MeOH followed by 5% AcOH/MeOH. The product fractions werecombined and concentrated in vacuo to afford the title compound as anoff white solid (30 mg, 35%). NMR; δ_(H) (400 MHz, d⁶-DMSO) 0.89 (t, 3H,J=7.5 Hz), 1.23-1.34 (m, 2H), 1.55-1.65 (m, 2H), 3.85 (t, 2H, J=7 Hz),11.17 (s, 1H), 14.37 (br.s, 1H); m/z 243.3 [MH⁺].

Example 11 8-Chloro-3-propyl-3,7-dihydro-1H-purine-2,6-dione

3-Propyl-3,7-dihydro-1H-purine-2,6-dione (J. Med. Chem., 1993, 36 (10),1380-6) (0.3 g, 1.5 mmol) and N-chlorosuccinimide (0.21 g, 1.5 mmol)were dissolved in DMF (5 ml) and the solution stirred for 5 h. Thesolution was concentrated and the solid residues washed with methanoland filtered to provide the product as a white solid (0.148 g, 42%).NMR; δ_(H) (400 MHz, d⁶-DMSO) 0.85 (t, 3H, J=7 Hz), 1.65 (m, 2H), 3.8(t, 2H, J=7 Hz), 11.2 (s, 1H), one exchangeable not observed to δ_(H)13; m/z 229 [MH⁺]

Example 12 8-chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

a) 8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100 mg, 0.44mmol) in anhydrous DMF (3 ml) was added sodium carbonate (0.051 g, 0.484mmol). After 10 minutes stirring at room temperature pentyl iodide(0.063 ml, 0.484 mmol) was added and stirring continued under nitrogenat room temperature for 18 hours. The reaction mixture was diluted withwater (25 ml) and extracted with EtOAc (2×25 ml). The combined organicextracts were dried (MgSO₄) filtered and evaporated. Purification by SPE(Si, 5 g) eluting with 4:1 EtOAc/cyclohexane afforded the title compoundas a white solid (96 mg, 74%); m/z 297.2 [MH⁺].

b) 8-chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

A flask containing tetrakis(triphenylphosphine)-palladium (0) (56 mg,0.049 mmol) was flushed with nitrogen, before a solution of8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (96mg, 0.323 mmol) in anhydrous THF (1.5 ml) was added, followed by DMSO(0.1 ml) and morpholine (0.28 ml, 0.049 mmol). The resulting mixture wasstirred at room temperature under nitrogen for 72 hours. The reactionmixture was dissolved in EtOAc (25 ml) and washed with 2M HCl aq. (25ml). The organic extract was dried (MgSO₄) filtered and evaporated underreduced pressure. Purification by amino propyl SPE (2 g) loading andwashing with methanol and then eluting the product with 5% acetic acidin methanol. Evaporation of fractions containing product afforded thetitle compound as a white solid (27 mg, 33%). NMR; δ_(H) (400 MHz,d⁶-DMSO) 0.85 (t, 3H, J=7 Hz), 1.20-1.34 (m, 4H), 1.57-1.67 (m, 2H),3.84 (t, 2H, J=7 Hz), 11.19 (s, 1H), 14.38 (br. s, 1H); m/z 257.2 [MH⁺].

Example 13 8-chloro-3-(3-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-3-(3-methylbutyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

A solution of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(1.5 g, 6.6 mmol) in DMF (40 ml) was treated with sodium carbonate (0.9g, 8.5 mmol) and 1-bromo-3-methylbutane (1.04 g, 6.9 mmol). The stirredmixture was heated at 50° C. for 18 hours then cooled and evaporated todryness. The residue was treated with water (60 ml) and extracted withethyl acetate (3×80 ml). The organic fractions were combined, dried overmagnesium sulfate, filtered and evaporated. The residue was trituratedwith a mixture of diethyl ether and cyclohexane to reveal the product asa white solid which was filtered off and dried. This gave the titlecompound as a white solid m/z 297 [MH⁺].

b) 8-chloro-3-(3-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione

A solution of8-chloro-3-(3-methylbutyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(0.074 g, 0.25 mmol) in THF (2 ml) was treated with morpholine (0.035ml, 4.0 mmol) and the mixture degassed by the repeated alternateapplication of vacuum and nitrogen to the reaction vessel. The mixturewas then treated with a solution oftetrakis(triphenylphosphine)palladium(0) (0.03 g, 0.026 mmol) indegassed THF (0.5 ml). After 2 hours the mixture was treated with 2Maqueous hydrochloric acid (2 ml) and diethyl ether (3 ml). Theprecipitated product was filtered off, washed with diethyl ether anddried. This yielded the title compound as a white solid (0.036 g, 56%).NMR δ_(H) (400 MHz, d⁶-DMSO); 0.91 (d, 6H, J=6.3 Hz), 1.47-1.62 (m, 3H),3.87 (t, 2H, J=7.5 Hz), 11.19 (br. s, 1H), 14.38 (br. s, 1H); m/z 257,259 [MH⁺].

Example 144-(8-chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile

Prepared as example 13 using 4-bromobutyronitrile as alkylating agent

NMR δ_(H) (400 MHz, d⁶-DMSO); 1.89-2.00 (m, 2H), 2.55 (t, 2H, J=7.0 Hz),3.95 (t, 2H, J=6.5 Hz), 11.25 (br. s, 1H), 14.40 (br. s, 1H); m/z 254[MH⁺].

Example 158-chloro-3-(2-cyclohexylethyl)-3,7-dihydro-1H-purine-2,6-dione

8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100 mg,0.442 mmol) was stirred with sodium carbonate (52 mg, 0.486 mmol) in dryDMF (3 ml) for 30 min. Cyclohexylethyl bromide (93 mg, 0.486 mmol) wasadded, and the mixture was stirred at 37-40° C. under nitrogen for 65 h,followed by heating at 90° C. for 18 h. After cooling, the solution wasdegassed by evacuating and introducing nitrogen several times, andtetrakis(triphenylphosphine)palladium(0) (76 mg, 0.066 mmol) andmorpholine (0.385 ml, 4.42 mmol) were added and the mixture stirred for18 h. A further quantity of tetrakis(triphenylphosphine)palladium(0) (50mg, 0.043 mmol) and morpholine (0.2 ml) were added and stirringcontinued for a further 1 h. Ethyl acetate and 2M aqueous HCl were added(ca. 10 ml each) and the organic layer separated, washed with brine andevaporated. The residue was dissolved in THF and loaded onto a 5 gaminopropyl SPE cartridge. The cartridge was washed with THF followed byMeOH, and the acidic product eluted with AcOH in MeOH (5% rising to10%). The product thus obtained was further purified by autoprep HPLC toprovide the title compound, 5.5 mg, 3%

NMR δ_(H) (400 MHz, d⁶-DMSO) 0.80-0.95 (m, 2H), 1.05-1.35 (m, 4H),1.45-1.55 (m, 2H), 1.55-1.70 (m, 3H), 1.70-1.80 (m, 2H), 3.86 (t, 2H,J=8 Hz), 11.07 (s, 1H), one exchangeable not observed. m/z 297 (MH⁺),

Example 163-butyl-1-methyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

a) 3-butyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

A stirred solution of 7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(10 g, 52 mmol) in anhydrous DMF (100 ml) was treated with K₂CO₃ (7.91g, 57.2 mmol) and, after 10 minutes, Bul (6.51 ml, 57.2 mmol). Afterreacting for 2 days the reaction mixture was partitioned between 2MHCl(aq) and EtOAc. The organic layer was separated, washed with brine,dried (MgSO₄) and concentrated in vacuo to give an off-white solid. Thiswas washed with hot cyclohexane and dried under vacuum to give the titlecompound (8.87 g, 68%); m/z 249.3 [MH⁺].

b) 3-butyl-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

A stirred solution of3-butyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.0 g, 4.03mmol) in anhydrous DMF (10 ml) was treated with Na₂CO₃ (470 mg, 4.43mmol) followed by Methyliodide (275 ul, 4.43 mmol). The mixture washeated at 35° C. for 17 hours. K₂CO₃ (500 mg, 3.6 mmol) and Methyliodide(275 ul, 4.43 mmol) were added and then stirred at 50° C. for a further18 hours. The reaction mixture was allowed to cool then partitionedbetween 2M HCl(aq) and EtOAc. The organic layer was separated and theaqueous extracted once more with EtOAc. The combined extracts werewashed with brine, dried (MgSO₄) and concentrated giving a yellow/brownoil (1.24 g). The product was purified by silica SPE (10 g), elutingwith EtOAc/cyclohexane mixtures. The product fractions were combined andconcentrated to afford the title compound as a pale yellow solid (1.11g, quant.); m/z 263.3 [MH⁺].

c)3-butyl-1-methyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbaldehyde

A pre-dried flask was charged with3-butyl-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (300mg, 1.14 mmol) and anhydrous THF (6 ml), cooled to −75° C. undernitrogen, then treated with LiHMDS (1.37 ml of a 1.0M solution in THF).The resulting solution was allowed to warm to −60° C. over 1.5 hoursbefore the addition of anhydrous DMF (177 ul, 2.29 mmol). The solutionwas allowed to warm to −10° C. over 3 hours then it was quenched withsat. NH₄Cl (aq) solution. The mixture was partitioned between 1M HCl(aq) and EtOAc. The organic layer was separated, washed with brine,dried (MgSO₄) and concentrated giving a brown oil (350 mg). The productwas purified by SPE (Si, 10 g) eluting with EtOAc/cyclohexane mixturesto give the title compound as a white solid (131 mg, 39%); NMR; δ_(H)(400 MHz, d⁶-DMSO) 0.91 (t, 3H, J=7.5 Hz), 1.28-1.39 (m, 2H), 1.63-1.73(m, 2H), 3.25 (s, 3H), 4.02 (t, 2H, J=7.5 Hz), 5.03 (dd, 1H, J=17 and 1Hz), 5.17 (dd, 1H, J=10 and 1 Hz), 5.31 (app. d, 2H, J=5.5 Hz),5.98-6.09 (m, 1H), 9.88 (s, 1H).

d)3-butyl-1-methyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

A solution of3-butyl-1-methyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbaldehydein anhydrous pyridine (5 ml) was treated with hydroxylaminehydrochloride (63 mg, 0.91 mmol) and heated at 50° C. for 1 hour. Themixture was allowed to cool, concentrated, and treated with aceticanhydride (5 ml) then heated at 100° C. for 2.5 hours and 125° C. for 45minutes. Again the mixture was allowed to cool then partitioned betweenwater and EtOAc. The organic layer was separated, washed with brine,dried (MgSO₄) and concentrated to afford the title compound as a yellowresidue (230 mg crude, 114%); m/z 288.3 [MH⁺].

e)3-butyl-1-methyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

A solution of3-butyl-1-methyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile(230 mg, 0.80 mmol) in anhydrous THF (5 ml) and anhydrous DMSO (0.5 ml)was treated with Pd(PPh₃)₄ (185 mg, 0.16 mmol). The mixture was degassedunder gentle vacuum, morpholine (698 uL) added, and left to stir at rtunder nitrogen for 2 hours. The yellow solution was partitioned between2M HCl(aq) and EtOAc. The organic layer was separated, washed withbrine, dried (MgSO₄) and concentrated. The residue was taken up in MeOHand passed down and amino-propyl SPE (5 g), eluting with MeOH followedby 5% AcOH then 10%, 20% and 30% AcOH/MeOH mixtures. The productfractions were combined and concentrated to afford a pale yellow solid(116 mg). This was washed with MeOH and the title compound a white solidwas collected by filtration and dried under vacuum (55 mg, 28%). NMR;δ_(H) (400 MHz, d⁶-DMSO) 0.90 (t, 3H, J=7.5 Hz), 1.25-1.35 (m, 2H),1.59-1.68 (m, 2H), 3.24 (s, 3H), 3.96 (t, 2H, J=7 Hz), NH not observedto δ_(H) 15; m/z 248.2 [MH⁺].

Example 171-Methyl-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

a) 3-Pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (0.61 g, 3.2 mmol),sodium carbonate (0.60 g, 5.7 mmol) and pentyl iodide (0.64 g, 3.2 mmol)were stirred in DMF (5 ml) at 50° C. for 18 h. The solution was cooled,separated between ethyl acetate and brine and the organics isolated,dried (MgSO₄) and concentrated. Chromatography over silica (gradientelution dichloromethane to 5:1 dichloromethane/ethyl acetate) providedthe title compound as a pale yellow solid (0.47 g, 56%). m/z 263 [MH⁺]

b) 1-methyl-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

3-Pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (0.20 g, 0.76mmol), potassium carbonate (0.4 g, 2.9 mmol) and methyl iodide (0.5 ml,4.9 mmol) were stirred and heated at 50° C. in DMF (5 ml) for 3 h. Thesolution was allowed to cool and separated between ethyl acetate andbrine. The organics were isolated, dried (MgSO₄) and concentrated toprovide the title compound (0.21 g, 100%). m/z 277 [MH⁺]

c)1-Methyl-,6-dioxo-3-pentyl-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbaldehyde

To 1-methyl-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(1.05 g, 3.6 mmol) in THF (15 ml) at −78° C. was added LiHMDS (4 ml, 1Min hexane, 4 mmol) over 10 min and the solution stirred for 0.5 h. DMF(0.5 ml) was added and the solution stirred at −78° C. for a further 0.5h then allowed to warm to ambient temperature with the cooling bath over2 h. The reaction was quenched with 2N hydrochloric acid (3 ml) andpartioned between ethyl acetate and brine. The organics were isolated,dried and concentrated. The crude product was chromatographed oversilica (gradient elution dichloromethane to 5:1 dichloromethane/ethylacetate) to afford the title compound as a white solid (0.35 g, 30%).m/z 305 [MH⁺]

d)1-Methyl-2,6-dioxo-3-pentyl-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

1-Methyl-2,6-dioxo-3-pentyl-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbaldehyde(0.18 g, 0.6 mmol) and hydroxylamine hydrochloride (0.053 g, 0.76 mmol)were heated at 50° C. in pyridine (5 ml) for 1 h then cooled to ambient.Acetic anhydride (0.08 g, 0.78 mmol) was added and the solution stirredfor 18 h. The solution was concentrated to provide the acetate anddissolved in acetic anhydride (3 ml) and heated to 130° C. for 3 h,cooled and concentrated to yield crude product. Chromatography oversilica (eluting with dichloromethane) yielded the title compound as aclear oil (0.17 g, 95%). m/z 302 [MH⁺]

e)1-Methyl-2,6-dioxo-3-pentyl-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

1-Methyl-2,6-dioxo-3-pentyl-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile(0.17 g, 0.56 mmol) and morpholine (0.6 ml, 6.7 mmol) were dissolved inTHF (5 ml) containing DMSO (0.5 ml). The flask containing the solutionwas placed under vacuum and the air replaced with nitrogen (×3).Tetrakis(triphenylphosphine)palladium (0) (0.13 g, 0.11 mmol) was addedand the solution stirred for 2.5 h. The solution was separated betweenethyl acetate (20 ml) and 2N hydrochloric acid (10 ml) and the organicsisolated and washed with brine (3×10 ml). The organics were then washedwith 2N sodium hydroxide solution (2×10 ml) and the aqueous acidifiedwith 2N hydrochloric acid and extracted with ethyl acetate (2×10 ml).The organics were isolated, dried (MgSO₄) and concentrated to yield thetitle compound (0.026 g, 18%). NMR; δ_(H) (400 MHz, CDCl₃) 0.92 (t, 3H,J=7 Hz), 1.32-1.43 (m, 4H), 1.79 (m, 2H), 3.54 (s, 3H), 4.15 (t, 2H,J=7.5 Hz), 14.35 (br. s, 1H); m/z 262 [MH⁺]

Example 18 8-chloro-3-hexyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (6 g, 26.5mmol) in anhydrous DMF (30 ml) was added sodium carbonate (3.09 g, 29.15mmol). After 10 minutes stirring at room temperaturemethoxyethoxymethylchloride (3.03 ml, 26.5 mmol) was added and stirringcontinued under nitrogen at room temperature for 66 hours. The reactionmixture was concentrated in vacuo and the residue dissolved in EtOAc(100 ml) and washed with brine (100 ml), the aqueous extract wasextracted with DCM (100 ml) and the organic extracts dried (MgSO₄)combined and concentrated in vacuo. The residue was triturated withEtOAc and the solid filtered off. Concentration of the filtrate affordeda light brown oil that was absorbed onto silica and purified by SPE (Si,50 g) eluting with a gradient of 1:1 EtOAc/cyclohexane-EtOAc to affordthe title compound as a white solid (2 g, 24%), m/z 315.2 [MH⁺].

b)8-chloro-1-methyl-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(2 g, 6.37 mmol) in anhydrous DMF (15 ml) was added sodium carbonate(0.743 g, 7 mmol). After 10 minutes stirring at room temperaturemethyliodide (0.44 ml, 7 mmol) was added and stirring continued undernitrogen at room temperature for 18 hours. The reaction mixture wasconcentrated in vacuo and the residue dissolved in EtOAc (100 ml) andwashed with brine (100 ml). The organic extract was dried (MgSO₄)filtered and evaporated to afford the title compound as a tan oil (85%pure) (2.98 g, quant.), m/z 329.2 [MH⁺].

c) 8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-1-methyl-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(2.9 g, 6.37 mmol) in dioxan (20 ml) and water (20 ml) was added 5M HCl(20 ml). The resulting mixture was heated at 100° C. under nitrogen for18 hours. The reaction mixture was then concentrated in vacuo, theresidue was dissolved in EtOAc (100 ml) and washed with water. Theorganic extract was dried (MgSO₄) filtered and evaporated. Purificationby SPE (Si, 20 g) eluting 2:3 EtOAc/cyclohexane afforded the titlecompound as a white solid (1.04 g, 68%). m/z 241.1 [MH⁺].

Alternatively8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione canbe prepared with SEM protection.

a)8-chloro-7-(2-propen-1-yl)-3-({[2-(trimethylsilyl)ethyl]oxy}methyl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (5 g, 22.1mmol) in DMF (80 ml) was added 2-2-(trimethylsilyl)ethoxymethyl chloride(4.3 ml, 24.2 mmol) and sodium carbonate (2.6 g, 24.2 mmol). Afterstirring overnight at room temperature overnight further2-2-(trimethylsilyl)ethoxymethyl chloride (4.3 ml, 24.2 mmol) and sodiumcarbonate (1.3 g, 12.1 mmol) were added and stirring continued for 2hours. The reaction mixture was then partitioned between 5% LiCl aq andethylacetate. The organic extract was separated, washed with brine,dried (MgSO₄) and concentrated. Purification by Biotage™ chromatographyusing a silica cartridge eluting 1:4-1:2 ethyl acetate/cyclohexanteafforded the title compound (3.14 g, 40%); m/z 374.2 [MNH₄ ⁺].

b)8-chloro-1-methyl-7-(2-propen-1-yl)-3-({[2-(trimethylsilyl)ethyl]oxy}methyl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3-({[2-(trimethylsilyl)ethyl]oxy}methyl)-3,7-dihydro-1H-purine-2,6-dione(3.14 g, 8.82 mmol) in DMF (50 ml) was added methyl iodide (0.659 ml,10.58 mmol) and caesium carbonate (3.45 g, 10.58 mmol) and the reactionmixture stirred overnight at room temperature. The reaction mixture waspartioned between water and ethyl acetate. The organic extract wasseparated, washed with brine, dried (MgSO₄) and concentrated to affordthe title compound 2.99 g (92%); m/z 388 [MH⁺].

c) 8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-1-methyl-7-(2-propen-1-yl)-3-({[2-(trimethylsilyl)ethyl]oxy}methyl)-3,7-dihydro-1H-purine-2,6-dione(2.99 g, 8.08 mmol) in DCM (20 ml) was added TFA (10 ml) and thereaction stirred for 2.5 hours at room temperature. The reaction mixturewas then concentrated and the residue treated with further DCM andevaporated once more. Purification by SPE (Si) eluting 1:9-4:1ethylacetate/cyclohexane afforded impure product (1.31 g), which wasdissolved in methanol (20 ml) and treated with sat. potassium carbonateaq. (20 ml). After stirring overnight the mixture was partitionedbetween water containing 2M HCl (1 ml) and ethyl acetate. The organicextract was separated, washed with brine, dried (MgSO₄) and concentratedto afford the title compound 0.87 g (45%); m/z 241.1 [MH⁺].

d) 8-chloro-3-hexyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100mg, 0.42 mmol) in anhydrous DMF (3 ml) was added sodium carbonate (58mg, 0.54 mmol), after 10 minutes stirring hexyl iodide (0.08 ml, 0.54mmol) was added and the reaction mixture stirred at room temperatureunder nitrogen for 90 hours. Pd(PPh₃)₄ (73 mg, 0.063 mmol) was thenadded and the reaction vessel evacuated and flushed with nitrogen (×3),morpholine (0.37 ml, 4.3 mmol) was added and stirring at roomtemperature under nitrogen continued for 4 hours. The reaction mixturewas diluted with EtOAc (25 ml) and washed with 2M HCl aq. (25 ml). Theorganic extract was dried (MgSO₄) filtered and evaporated. Purificationby aminopropyl SPE (5 g) loading the compound and washing with MeOHbefore eluting the product with 5% AcOH/MeOH afforded the title compoundas a white solid (65 mg, 54%). NMR; δ_(H) (400 MHz, d⁶-DMSO)) 0.85 (t,3H, J=7 Hz), 1.23-1.33 (m, 6H), 1.58-1.68 (m, 2H), 3.22 (s, 3H), 3.91(t, 2H, J=7.5 Hz), 14.46 (br. s, 1H); m/z 285.3 [MH⁺].

Example 19 8-chloro-1-methyl-3-propyl-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 18 but using propyl iodide toalkylate on N3.

NMR δ_(H) (400 MHz, d⁶-DMSO) 0.87 (t, 3H, J=7.5 Hz), 1.61-1.73 (m, 2H),3.22 (s, 3H), 3.89 (t, 2H, J=7.5 Hz), 14.45 (br. s, 1H), m/z 243 [MH⁺]

Example 201,3-dibutyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

a) 1,3-dibutyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

A solution of 1,3-di-N-butyl xanthine (10 g, 38 mmol) in anhydrous DMF(80 ml) was treated with K₂CO₃ (5.2 g, 38 mmol) followed by allylbromide (3.6 ml, 42 mmol). The mixture was heated at 55° C. undernitrogen for 18 hours. After cooling to rt the mixture was partitionedbetween water and EtOAc. A few mls of 2M HCl(aq) was added to aidseparation. The organic layer was separated and the aqueous extractedonce more with EtOAc. The combined extracts were washed with brine,dried (MgSO₄) and concentrated to afford the title compound as anoff-white solid (12.23 g, 106%). m/z 305.3 [MH⁺].

b) Methyl1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carboxylate

A solution of1,3-dibutyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (3.0 g,9.9 mmol) in anhydrous THF (30 ml) was cooled to −50° C. and treatedwith LiHMDS (18 ml of a 1.0M solution in THF, 17.8 mmol). After 1 hourat −50° C. methyl chloroformate (1.9 ml, 24.6 mmol) was added and themixture allowed to warm to −30° C. over 2 hours, then quenched with sat.NH₄Cl (aq) solution. The mixture was partitioned between EtOAc and 1MHCl (aq). The organic layer was separated, washed with brine, dried(MgSO₄) and concentrated giving a dark orange oil (4.07 g). The oil wastaken up in 15% EtOAc/cyclohexane and passed down a Si Biotage™chromatography column. The product fractions were combined andconcentrated to afford the title compound as a yellow solid (1.35 g,38%). m/z 363.2 [MH⁺].

c)1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carboxylicacid

A stirred solution of methyl1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carboxylate(1.30 g, 3.6 mmol) in MeOH (15 ml) was treated with LiOH (215 mg) andwater (1.5 ml). After 3 hours at rt the mixture was diluted with waterand the pH adjusted to ca. pH5 with 2M HCl(aq). EtOAc was added and thenseparated, washed with brine, dried (MgSO₄) and concentrated to affordthe title compound as a yellow solid 85% pure (1.2 g, 88%). m/z. 349.2[MH⁺].

d)1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carboxamide

A stirred solution of1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carboxylicacid (1.0 g, 2.9 mmol) in anhydrous DMF (10 ml) was sequentially treatedwith DIPEA (1.1 ml), PyBOP, and 2M NH₃ (3.6 ml). After 2 hours theproduct mixture was partitioned between 2M HCl(aq) and EtOAc. Theorganic layer was separated, washed with sat. NaHCO₃(aq) solution,brine, then dried (MgSO₄) and concentrated giving an orange oil (ca. 2g). The product was purified by Biotage™ chromatography eluting with5%→40% EtOAc/cyclohexane mixtures. The appropriate fractions werecombined and concentrated to give the amide 90% pure (790 mg, 78%). m/z.392.3 [M+formic acid-H]⁻.

e)1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

A solution of1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carboxamide(300 mg) in anhydrous DMF (7 ml) at 0° C. was treated dropwise withPOCl₃ (237 uL). The ice-bath was removed and after 2 hours the mixturewas partitioned between water and Et₂O. The aqueous layer wasre-extracted with Et₂O and the combined extracts separated, washed withwater (×2), brine, then dried (MgSO₄) and concentrated, giving a yellowoil (312 mg). The oil was taken up in cyclohexane and purified by SPE(Si, 10 g) eluting with EtOAc/cyclohexane mixtures. Concentration of theproduct fractions gave the title compound as a colourless oil (150 mg,53%); m/z. 330.3 [MH⁺].

f) 1,3-dibutyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile

A solution of1,3-dibutyl-2,6-dioxo-7-(2-propen-1-yl)-2,3,6,7-tetrahydro-1H-purine-8-carbonitrile(140 mg, 0.43 mmol) in anhydrous THF (4 ml) and anhydrous DMSO (0.4 ml)was treated with Pd(PPh₃)₄ (74 mg, 0.064 mmol). The mixture was degassedunder gentle vacuum, morpholine (371 uL) added, and left to stir at rtunder nitrogen for 4 hours. The yellow solution was partitioned between2M HCl(aq) and EtOAc. The organic layer was separated, washed withbrine, dried (MgSO₄) and concentrated. The residue was taken up in MeOHand passed down and amino-propyl SPE (5 g), eluting with MeOH followedby 5%→50% AcOH/MeOH. The product eluted with a small impurity which waswashed out, after concentrating, with cyclohexane to afford the titlecompound as an off-white solid (30 mg, 24%). NMR δ_(H) (400 MHz,d⁶-DMSO) 0.89 (app. td, 6H, J=7 and 3 Hz), 1.25-1.35 (m, 4H), 12.48-1.55(m, 2H), 1.58-1.69 (m, 2H), 3.87 (t, 2H, J=7 Hz), 3.95 (t, 2H, J=7 Hz),NH not observed to δ_(H) 15; m/z 290.3 [MH⁺].

Example 21 1,3-dibutyl-8-iodo-3,7-dihydro-1H-purine-2,6-dione

A stirred solution of 1,3-di-N-butyl xanthine (100 mg, 3.39 mmol) inanhydrous DMF (3 ml) was treated with NIS (94 mg, 3.75 mmol) and left tostir at rt. under nitrogen for 23 hours. The mixture was partitionedbetween sat. Na₂SO₃(aq) solution and EtOAc. The organic layer wasseparated, washed with brine, dried (MgSO₄) and concentrated in vacuo.The product was purified by passing down an SPE (Si, 5 g) cartridgeeluting with EtOAc/cyclohexane mixtures. The product fraction wasconcentrated to afford the title compound as a white solid (75 mg, 51%);NMR; δ_(H) (400 MHz, d⁶-DMSO) (app. td, 6H, J=7.5 and 4 Hz), 1.21-1.34(m, 4H), 1.45-1.54 (m, 2H), 1.56-1.66 (m, 2H), 3.84 (t, 2H, J=7.5 Hz),3.93 (t, 2H, J=7.5 Hz), 14.10 (s, 1H); m/z 391.3 [MH⁺].

Example 22(3-butyl-8-chloro-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile

To a mixture of3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (200mg, 0.707 mmol) and Cs₂CO₃ (254 mg, 0.778 mmol) in anhydrous DMF (5 ml)was added chloroacetonitrile (0.054 ml, 0.85 mmol). The mixture washeated at 50° C. for 18 hours then allowed to cool to rt and degassedunder a gentle vacuum then nitrogen introduced. This was repeated twice.Pd(PPh₃)₄ (82 mg, 0.071 mmol) was added and the mixture degassed oncemore, before morpholine (0.617 ml, 7.07 mmol) was added and the mixtureleft to stir for 3 hours at rt. The mixture was partitioned between 2MHCl(aq) and EtOAc. The organic layer was separated, washed with brine,dried (MgSO₄) and concentrated. The residue was taken up in MeOH andpassed down an amino-propyl SPE (5 g), eluting with MeOH followed by5-10% AcOH/MeOH. The product fraction was concentrated giving the titlecompound 52 mg (26%); NMR; δ_(H) (400 MHz, d⁶-DMSO) 0.90 (t, 3H, J=7.5Hz), 1.26-1.37 (m, 2H), 1.60-1.69 (m, 2H), 3.94 (t, 2H, J=7.5 Hz), 4.87(s, 2H), 14.72 (br s, 1H); m/z 299.2 [MNH₄ ⁺].

Example 23(8-chloro-2,6-dioxo-3-propyl-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile

a) 8-chloro-7-(2-propen-1-yl)-3-propyl-3,7-dihydro-1H-purine-2,6-dione

A mixture of 8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(1.5 g, 6.6 mmol), 1-iodopropane (1.2 g, 6.9 mmol) and sodium carbonate(0.9 g, 8.5 mmol) in DMF (40 ml) was heated at 50° C. for 18 hours. Thereaction mixture was concentrated in vacuo and the residue treated withwater (60 ml) and extracted with ethyl acetate (3×80 ml). The combinedorganic extracts were dried (MgSO₄) filtered and evaporated. The residuewas triturated with ether/cyclohexane, the solid was filtered off anddried to afford the title compound (0.82 g, 46%); m/z 269.1 [MH⁺].

b)(8-chloro-2,6-dioxo-3-propyl-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile

A solution of8-chloro-7-(2-propen-1-yl)-3-propyl-3,7-dihydro-1H-purine-2,6-dione(0.067 g, 0.25 mmol) in DMF (2 ml) was treated with caesium carbonate(0.082 g, 0.25 mmol) and bromoacetonitrile (0.044 g, 0.37 mmol). Themixture was heated at 80° C. for 4 hours then cooled to ambienttemperature. The DMF was removed in vacuo and the residue treated withTHF (2 ml). The solvent was degassed by the successive application ofvacuum and nitrogen pressure to the reaction mixture. The mixture wasthen treated with morpholine (0.035 ml, 0.4 mmol) andtetrakis(triphenylphosphine)palladium(0) (0.03 g, 0.026 mmol). After 2hours the mixture was treated with 2M aqueous hydrochloric acid (2 ml)and the product extracted with chloroform (3×5 ml). The organicfractions were combined and evaporated. The residue was subjected topurification by mass-directed HPLC to afford the title compound as awhite solid (0.022 g, 33%). NMR; δ_(H) (400 MHz, d⁶-DMSO), 0.88 (t, 3H,J=7.5 Hz), 1.63-1.74 (m, 2H), 3.91 (t, 2H, J=7.5 Hz), 4.87 (s, 2H), NHnot observed to δ_(H) 14; m/z 268 [MH⁺].

Example 24[8-chloro-3-(2-cyclopropylethyl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl]acetonitrile

Prepared as(8-chloro-2,6-dioxo-3-propyl-2,3,6,7-tetrahydro-1H-purin-1-yl)acetonitrile(example 23) using8-chloro-3-(2-cyclopropylethyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione.

NMR δ_(H) (400 MHz, d⁶-DMSO) −0.06-0.00 (m, 2H), 0.31-0.39 (m, 2H),0.64-0.74 (m, 1H), 1.57 (q, 2H, J=7 Hz), 4.04 (t, 2H, J=7 Hz), 4.87 (s,2H), 14.68 (br. s, 1H); m/z 294 [MH⁺].

Example 258-chloro-1-ethyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-7-(2-propen-1-yl)-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (1.5 g, 6.62mmol) in anhydrous DMF (50 ml) was added sodium bicarbonate (0.98 g,9.25 mmol) followed by 1,1,1-trifluoro-2-iodoethane (1.20 g, 5.72 mmol)and the mixture heated with stirring for 6 h at 50° C. under anatmosphere of nitrogen. The solution was allowed to cool to ambienttemperature for 10 h then heated for 48 h at 120° C. Additional1,1,1-trifluoro-2-iodoethane (0.43 g, 2.05 mmol) was added and themixture heated to 120° C. for a further 3 h. The solvent was removedunder reduced pressure and the residue triturated with DCM thenfiltered.

The reaction was repeated using8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (3.80 g, 16.8mmol), sodium bicarbonate (2.45 g, 23.1 mmol) and1,1,1-trifluoro-2-iodoethane (4.05 g, 19.3 mmol) in anhydrous DMF (125ml). The mixture was heated for 16 h at 120° C., the solvent removedunder reduced pressure and the residue triturated with DCM thenfiltered.

DCM filtrates from the two runs were combined, concentrated underreduced pressure then purified using Biotage™ chromatography (elutingwith cyclohexane/ethyl acetate 1:1, then 7:3) to give the title compoundas a white solid (1.6 g, 23%). m/z 309 [MH⁺].

b)8-chloro-1-ethyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione(0.070 g, 0.23 mmol) in anhydrous DMF (2 ml) was added caesium carbonate(0.085 g, 0.26 mmol) followed by 1-iodoethane (0.061 g, 0.39 mmol). Themixture was heated for 5 h at 80° C. then stirred for 16 h at ambienttemperature under an atmosphere of nitrogen. The solvent was removedunder reduced pressure using a vacuum centrifuge and the residuedissolved in anhydrous THF (2.5 ml). To the mixture was added palladiumtetrakis (0.030 g, 0.026 mmol) and morpholine (0.040 g, 0.45 mmol) andthe reaction mixture degassed using nitrogen then stirred at ambienttemperature for 72 h. The mixture was partitioned between chloroform and2N HCl aq., and the aqueous layer re-extracted. Organic extracts werecombined and evaporated under a stream of nitrogen then purified usingaminopropyl SPE (eluting with acetic acid:methanol:DCM, 1:2:2) to givethe title compound as a white solid in >95% purity (0.041 g, 60%). NMRδ_(H) (400 MHz, d⁴-MeOD) 1.20 (t, 3H, J=7 Hz), 4.03 (q, 2H, J=7 Hz),4.73 (q, 2H, J=8.5 Hz), m/z 297 [MH⁺].

Example 268-chloro-1-propyl-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 25 using propyl iodide toalkylate on N1.

NMR δ_(H) (400 MHz, CDCl₃) 0.99 (t, 3H, J=7.5 Hz), 1.68-1.79 (m, 2H),4.07 (t, 2H, J=7.5 Hz), 4.77 (q, 2H, J=8.5 Hz), NH not observed to δ_(H)13; m/z 311 [MH⁺].

Example 278-chloro-1-(4,4,4-trifluorobutyl)-3-(2,2,2-trifluoroethyl)-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 25 using4-bromo-1,1,1-trifluorobutane to alkylate on N1. NMR; δ_(H) (400 MHz,d⁴-MeOD) 1.83-1.95 (m, 2H), 2.14-2.32 (m, 2H), 4.06 (t, 2H, J=7 Hz),4.74 (q, 2H, J=8.5 Hz), m/z 377 [M-H]⁻.

Example 28 8-Bromo-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

a) 1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

1-methyl-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(0.45 g, 1.63 mmol), phenylsilane (0.25 ml, 2.03 mmol) andtetrakis(triphenylphosphine)palladium(0) (0.35 g, 0.3 mmol) wasdissolved in DCM (10 ml) containing acetic acid (6 ml). The air in theflask was replaced by nitrogen by evacuating the flask then filling withnitrogen (×3) and the reaction mixture heated to 45 C for 4 h. Thesolution was allowed to cool diluted with DCM then washed with waterthen saturated sodium bicarbonate solution. The organics were isolated,dried and concentrated to yield crude product. Purification by SPE(silica) eluting with ether provided the product, 0.06 g, 16%. m/z 237[MH⁺].

b) 8-Bromo-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione (0.06 g, 0.25 mmol)was dissolved in DMF (2 ml) and N-bromosuccinamide (0.045 g, 0.25 mmol)added. The mixture was stirred for 18 h, concentrated and the crudepurified by eluting through an aminopropyl SPE (5 g) with first methanolthen 5% acetic acid/methanol to elute product. The product was furtherpurified by mass directed auto prep to yield the title compound as awhite solid (0.01 g, 12%). NMR δ_(H) (400 MHz, d⁶-DMSO) 0.86 (t, 3H, J=7Hz), 1.21-1.35 (m, 4H), 1.59-1.68 (m, 2H), 3.22 (s, 3H), 3.91 (t, 2H,J=7.5 Hz), 14.39 (br. s, 1H); m/z 315, 317 [MH⁺].

Example 29 8-chloro-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-1-methyl-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (3.9g, 13.3 mmol) in DMF (35 ml) was added cesium carbonate and the mixturestirred for 10 min whereupon iodomethane (0.91 ml, 14.6 mmol) was addedand the mixture stirred for 18 h. The reaction was partitioned betweenethyl acetate and 2N HCl solution and the organics isolated, dried(MgSO₄) and concentrated. Chromatography on silica SPE eluting withcyclohexane/ethyl acetate (5%-20%) provided the product as an oil, 2.78g, 68%. m/z 311 [MH⁺].

b) 8-chloro-1-methyl-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

Tetrakis(triphenylphosphine)palladium (1.0, 0.90 mmol) was placed in aflask which was evacuated and then filled with nitrogen (×3). A solutionof8-chloro-1-methyl-3-pentyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(2.78 g, 8.96 mmol) in 50 ml of THF was added and the flask evacuatedonce more and nitrogen introduced. DMSO (4.5 ml) and morpholine (7.8 ml,89.6 mmol) was added and the solution stirred for 5 h. The solution waspartitioned between ethyl acetate and 2N HCl solution and the organicfraction washed with brine, dried (MgSO₄) and concentrated. The crudewas purified with an aminopropyl SPE eluting with first methanol thenmethanol containing 0-15% acetic acid to provide the title compound as awhite solid, 1.12 g, 46%. NMR δ_(H) (400 MHz, d⁶-DMSO) 0.86 (t, 3H, J=7Hz), 1.21-1.35 (m, 4H), 1.59-1.68 (m, 2H), 3.22 (s, 3H), 3.91 (t, 2H,J=7.5 Hz), NH not observed; m/z 271 [MH⁺].

Example 30 3-butyl-8-chloro-1-methyl-3,7-dihydro-1H-purine-2,6-dione

Prepared in similar fashion to Example 29 using3-butyl-8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione asthe starting material.

NMR δ_(H) (400 MHz, d⁶-DMSO) 0.88 (t, 3H, J=7 Hz), 1.25-1.35 (m, 2H),1.6-1.66 (m, 2H), 3.22 (s, 3H), 3.91 (t, 2H, J=7.5 Hz), 14.46 (br s,1H); m/z 257 [MH⁺].

Example 314-(8-chloro-1-methyl-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanenitrile

To a mixture of8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (70mg, 0.292 mmol) and Na₂CO₃ (37 mg, 0.35 mmol) in DMF (3 ml) was added4-bromobutyronitrile (0.035 ml, 0.35 mmol). The mixture was stirred atroom temperature overnight, before degassing under a gentle vacuum andintroducing nitrogen. Pd(PPh₃)₄ (50 mg, 0.044 mmol) and morpholine(0.254 ml, 2.92 mmol) was then added sequentially. After two hoursstirring at room temperature further fresh Pd(PPh₃)₄ (50 mg, 0.044 mmol)was added and stirring continued overnight. The reaction mixture waspartioned between ethyl acetate (20 ml) and water (20 ml) adding a smallamount of 2M HCl to aid separation. The organic layer was separated,washed with brine, dried (MgSO₄) and concentrated. The residue was takenup in MeOH and passed down an amino-propyl SPE (5 g), eluting with MeOHfollowed by 3-5% AcOH/MeOH. The product fraction was concentrated toafford the title compound 39.7 mg (51%); NMR; δ_(H) (400 MHz, d⁶-DMSO)1.91-2.00 (m, 2H), 2.55 (t, 2H, J=7 Hz), 3.22 (s, 3H), 4.03 (t, 2H, J=7Hz), 14.49 (br.s, 1H); m/z 268.1 [MH⁺].

Example 328-chloro-1-methyl-3-(4,4,4-trifluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

A solution of8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(0.048 g, 0.2 mmol) in THF (1 ml) was treated with caesium carbonate(0.78 g, 0.24 mmol) and 4-bromo-1,1,1-trifluorobutane (0.044 g, 0.25mmol). The mixture was stirred at ambient temperature for 1 hour thenheated at 50° C. for 4 hours and then cooled. The mixture was degassedby alternately applying vacuum and nitrogen pressure to the mixture andthen treated with morpholine (0.17 ml, 2 mmol) andtetrakis(triphenylphosphine)palladium(0) (0.023 g, 0.02 mmol). After 2hours the mixture was treated cautiously with 2M aqueous hydrochloricacid (2 ml) and the product extracted with chloroform (2×4 ml). Thecombined organics were evaporated and the product purified byreverse-phase mass directed HPLC to afford the title compound 6.2 mg(10%); NMR; δ_(H) (400 MHz, d⁶-DMSO); 1.84-1.92 (m, 2H), 2.28-2.35 (m,2H), 3.22 (s, 3H), 3.99-4.03 (m, 2H) 14.31 (br.s, 1H); m/z 311.2 [MH⁺].

Example 33 3-butyl-8-chloro-1-ethyl-3,7-dihydro-1H-purine-2,6-dione

a) 3-butyl-7-(phenylmethyl)-3,7-dihydro-1H-purine-2,6-dione

7-benzyl-3,7-dihydro-1H-purine-2,6-dione (17.14 g, 70.8 mmol) [SyntheticCommunications, 20(16), 2459-2467, 1990] and potassium carbonate (11.43g, 82.8 mmol) were suspended in DMF (400 mL) at 40° C. After stirringfor thirty minutes, butyl iodide (8.76 mL, 77.0 mmol) was added, and themixture was stirred at 40° C. overnight. 50% Aqueous acetic acid (60 mL)was added, and the solution was concentrated under reduced pressure. Theresidue was suspended in water (500 mL), and the products were extractedinto chloroform. The organics were collected, concentrated, and productwas isolated using flash chromatography eluting with 1% methanol indichloromethane to provide the product (9.49 g, 45%); ¹H NMR (400 MHz;CDCl₃) δ: 0.95 (3H, t), 1.34-1.41 (2H, m), 1.70-1.78 (2H, m), 4.05 (2H,t), 5.46 (2H, s), 7.31-7.40 (5H, m), 7.56 (1H, s), 8.21 (1H, br.s); m/z299 [MH⁺].

b) 3-butyl-1-ethyl-7-(phenylmethyl)-3,7-dihydro-1H-purine-2,6-dione

3-butyl-7-(phenylmethyl)-3,7-dihydro-1H-purine-2,6-dione (0.429 g, 1.24mmol) and potassium carbonate (0.256 g, 1.85 mmol) were suspended in DMF(8 mL), iodoethane (0.113 mL, 1.42 mmol) was added. The reaction mixturewas stirred at ambient temperature overnight. The reaction mixture wasevaporated to dryness and the residue was partitioned between water andethyl acetate. The organic layer was washed with water, followed bybrine, dried over anhydrous sodium sulphate and concentrated underreduced pressure to yield the title compound; ¹H NMR (400 MHz; CDCl₃) δ:0.96 (3H, t), 1.25 (3H, t), 1.36-1.45 (2H, m), 1.72-1.76 (2H, m),4.05-4.13 (4H, m), 5.50 (2H, s), 7.32-7.40 (5H, m), 7.52 (1H, s); m/z327 [MH⁺].

c) 3-Butyl-1-ethyl-3,7-dihydro-1H-purine-2,6-dione

3-butyl-1-ethyl-7-(phenylmethyl)-3,7-dihydro-1H-purine-2,6-dione (0.353g, 1.08 mmol) was dissolved in acetic acid (30 mL), 20% palladiumhydroxide on carbon (0.238 g) was added, and the mixture was shakenunder hydrogen (at 50 psi) overnight. The catalyst was removed byfiltration through Celite® and washed with acetic acid. The filtrate wasconcentrated under reduced pressure to yield the title compound (0.227g, 89%); ¹H NMR (400 MHz; CDCl₃) δ: 0.97 (3H, t), 1.28 (3H, t),1.38-1.47 (2H, m), 1.74-1.82 (2H, m), 4.12-4.17 (4H, m), 7.80 (1H, s);m/z 237 [MH⁺].

d) 3-Butyl-8-chloro-1-ethyl-3,7-dihydro-1H-purine-2,6-dione

3-Butyl-1-ethyl-3,7-dihydro-1H-purine-2,6-dione (100 mg, 0.42 mmol) andNCS (56 mg, 0.42 mmol) were suspended in MeCN (5 mL) and heated at 120°C. under microwave irradiation. The reaction mixture was concentratedunder reduced pressure and the title compound isolated using HPLC. [HPLCconditions used for the purification: 23 minute run time. Solvents: 0.1%TFA in MeCN and 0.1% TFA in water. MeCN increased from 5% to 95%linearly over 15 minutes. Held at 95% for 2 min. Then decreased to 5%linearly over 1 min., equilibrated at 5% for 5 minutes before nextinjection.]; ¹H NMR (400 MHz; CDCl₃) δ: 0.97 (3H, t), 1.31 (3H, t),1.38-1.45 (2H, m), 1.72-1.80 (2H, m), 4.09-4.20 (4H, m), 13.40 (1H,br.s); m/z 271 [MH⁺].

Example 34 8-Chloro-3-(4-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione

From 1-bromo-4-methylpentane (81 mg)Recrystallised from MeOH

Yield 34.8 mg (29%), NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.83 (d, 6H, J=8 Hz),1.12-1.22 (m, 2H), 1.55 (septet, 1H, J=8 Hz), 1.58-1.68 (m, 2H), 3.83(t, 2H, J=7.5 Hz), 11.20 (s, 1H); m/z 271 [MH⁺]

Example 356-(8-Chloro-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)-2,2-dimethylhexanenitrile

From 6-bromo-2,2-dimethylhexanenitrile (100 mg)Recrystallised from MeOH.

Yield 48.5 mg (35%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 1.27 (s, 6H),1.35-1.44 (m, 2H), 1.54-1.59 (m, 2H), 1.63-1.72 (m, 2H), 3.88 (t, 2H,J=7 Hz), 11.24 (s, 1H); m/z 310 [MH⁺]

Example 36 8-chloro-3-(6-methylheptyl)-3,7-dihydro-1H-purine-2,6-dione

From 1-bromo-6-methylheptane (95 mg)Recrystallised from MeOH.

Yield 36 mg (27%), NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.83 (d, 6H, J=7.5 Hz),1.10-1.17 (m, 2H), 1.20-1.34 (m, 4H), 1.48 (septet, 1H, J=7.5 Hz),1.58-1.68 (m, 2H), 3.84 (t, 2H, J=8 Hz), 11.22 (s, 1H); m/z 299 [MH⁺]

Example 37 8-Chloro-3-octyl-3,7-dihydro-1H-purine-2,6-dione

8-Chloro-3,7-dihydro-1H-purine-2,6-dione (100 mg, 0.44 mmol) was stirredwith sodium carbonate (52 mg, 0.49 mmol) in dry DMF (3 ml) for 20 min.,then 1-iodooctane (118 mg, 0.49 mmol) was added and the mixture wasstirred under nitrogen at 40 C for 65 h. After cooling to roomtemperature, the mixture was thoroughly degassed by evacuating thevessel and refilling with nitrogen several times.Tetrakis(triphenylphosphine)palladium(0) (102 mg, 0.09 mmol) was added,the mixture degassed again and then morpholine (0.385 ml, 4.4 mmol)added and stirring continued for 6.5 h. 2M HCl and EtOAc were added, andthe 2-phase system was filtered. The product was present predominantlyin the filtered solid, which was recrystallised from THF-acetonitrile,followed by MeOH, with filtration, to afford the pure title compound.

Yield 48 mg (36%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.84 (t, 3H, J=7 Hz),1.18-1.30 (m, 10H), 1.57-1.66 (m, 2H), 3.84 (t, 2H, J=7.5 Hz), 11.22 (s,1H); m/z 299 [MH⁺]

Example 38 8-Chloro-3-decyl-3,7-dihydro-1H-purine-2,6-dione

Prepared by the method of Example 37, starting from 1-bromodecane (108mg). Further purification was achieved by recrystallisation from MeOHfollowed by mass-directed autoprep.

Yield 2 mg (1.4%); NMR; (400 MHz, d⁴-methanol) δ_(H) 0.89 (t, 3H, J=7Hz), 1.26-1.38 (m, 14H), 1.68-1.76 (m, 2H), 3.97 (t, 2H, J=7.5 Hz); m/z327 [MH⁺].

Example 39 8-Chloro-3-(cyclohexylmethyl)-3,7-dihydro-1H-purine-2,6-dione

Prepared in a similar manner to Example 37, from(bromomethyl)cyclohexane (87 mg) except that an additional heatingperiod at 80 C for 18 h was performed.Recrystallised from MeOH.

Yield 31 mg (25%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.90-1.02 (m, 2H),1.08-1.20 (m, 3H), 1.53-1.69 (m, 5H), 1.77-1.87 (m, 1H), 3.70 (d, 2H,J=7.5 Hz), 11.21 (s, 1H); m/z 283 [MH⁺]

General Method for Examples 40-46:

To 8-chloro-3,7-dihydro-1H-purine-2,6-dione (100 mg, 0.442 mmol) in dryTHF (3 ml) was added the alcohol (0.442 mmol). The mixture was stirredat 0 C as a solution of dibenzyl azodicarboxylate (280 mg of 94% purity,0.88 mmol) in dry THF (2 ml) was added, followed by a solution oftriphenylphosphine (232 mg, 0.88 mmol) in dry THF, added portionwiseover 5 min. After a further 30 min at 0 C, stirring was continued atroom temperature for 18 h. The mixture was thoroughly degassed byevacuating and refilling the vessel with nitrogen several times, thentetrakis(triphenylphosphine)palladium(0) (102 mg, 0.088 mmol) was addedfollowed by morpholine (0.385 ml, 4.42 mmol) and stirring was continuedfor 4.5 h. EtOAc and 2M HCl were added, and the mixture filtered toremove a yellow precipitated solid. The filtrate was separated and theorganic phase concentrated and redissolved in a mixture of THF and MeOH.This solution was passed down an aminopropyl SPE, eluting with THF-MeOH(1:1) followed by MeOH and then 5% AcOH in DCM-MeOH (1:1). The productfractions thus obtained were concentrated and recrystallised from MeOHto afford the pure title compound.

Example 40(+/−)-8-Chloro-3-(3-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione

From (+/−)-3-methyl-1-pentanol 45 mg

Yield 20.2 mg (17%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.83 (t, 3H, J=7.5Hz), 0.90 (d, 3H, J=6.5 Hz), 1.12-1.21 (m, 1H), 1.30-1.48 (m, 3H),1.58-1.68 (m, 1H), 3.87 (t, 2H, J=7.5 Hz), 11.21 (s, 1H); m/z 271 [MH⁺].

Example 418-Chloro-3-(2-cyclopentylethyl)-3,7-dihydro-1H-purine-2,6-dione

From 2-cyclopentylethanol 50 mg

Yield 24.6 mg (20%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 1.04-1.15 (m, 2H),1.40-1.67 (m, 6H), 1.70-1.82 (m, 3H), 3.86 (t, 2H, J=7.5 Hz), 11.22 (s,1H); m/z 283 [MH⁺]

Example 428-Chloro-3-(cyclopropylmethyl)-3,7-dihydro-1H-purine-2,6-dione

From cyclopropylmethanol 32 mg

Yield 22.3 mg (21%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.34-0.40 (m, 2H),0.40-0.48 (m, 2H), 1.17-1.27 (m, 1H), 3.74 (d, 2H, J=7.5 Hz), 11.23 (s,1H); m/z 241 [MH⁺].

Example 43(+/−)-8-Chloro-3-(2-methylbutyl)-3,7-dihydro-1H-purine-2,6-dione

From (+/−)-2-methyl-1-butanol 39 mg

Yield 12 mg (9.5%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.81 (d, 3H, J=7 Hz),0.86 (t, 3H, J=7.5 Hz), 1.06-1.17 (m, 1H), 1.30-1.41 (m, 1H), 1.90-2.00(m, 1H), 3.68 (dd, 1H, J=13.5 and 8 Hz), 3.75 (dd, 1H, J=13.5 and 7.5Hz), 11.22 (s, 1H); m/z 257 [MH⁺]

Example 44(+/−)-8-Chloro-3-(2-methylpentyl)-3,7-dihydro-1H-purine-2,6-dione

From (+/−)-2-methyl-1-pentanol 45 mg

Yield 22.4 mg (19%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 0.81 (d, 3H, J=7 Hz),0.84 (t, 3H, J=7.5 Hz), 1.05-1.16 (m, 1H), 1.16-1.43 (m, 3H), 1.98-2.09(m, 1H), 3.67 (dd, 1H, J=13.5 and 8 Hz), 3.74 (dd, 1H, J=13.5 and 7 Hz),11.22 (s, 1H); m/z 271 [MH⁺]

Example 45 8-Chloro-3-(cyclobutylmethyl)-3,7-dihydro-1H-purine-2,6-dione

From cyclobutylmethanol 38 mg

Yield 30.5 mg (27%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 1.73-1.85 (m, 4H),1.86-1.97 (m, 2H), 2.66-2.79 (m, 1H), 3.90 (d, 2H, J=7.5 Hz), 11.22 (s,1H); m/z 255 [MH⁺]

Example 468-chloro-3-(cyclopentylmethyl)-3,7-dihydro-1H-purine-2,6-dione

From cyclopentylmethanol 44 mg

Yield 15 mg (13%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 1.20-1.32 (m, 2H),1.42-1.54 (m, 2H), 1.54-1.66 (m, 4H), 2.32-2.45 (m, 1H), 3.79 (d, 2H,J=8 Hz), 11.22 (s, 1H); m/z 269 [MH⁺]

Example 478-chloro-3-(3-cyclopropylpropyl)-3,7-dihydro-1H-purine-2,6-dione

From 3-cyclopropyl-1-propanol (P. J. Wagner, J. Amer. Chem. Soc., 1981,103, 3837-3841) (44 mg).

Yield 27.7 mg (23%); NMR; (400 MHz, d⁶-DMSO) δ_(H) −0.03-+0.03 (m, 2H),0.34-0.40 (m, 2H), 0.65-0.75 (m, 1H), 1.15-1.23 (m, 2H), 1.66-1.76 (m,2H), 3.87 (t, 2H, J=7 Hz), 11.15 (s, 1H); m/z 269 [MH⁺]

Example 488-chloro-3-(2-cyclobutylethyl)-3,7-dihydro-1H-purine-2,6-dione

From 2-cyclobutylethanol (P. Vergnon, Eur. J. Med. Chem., 1975, 10,65-71) (44 mg).

Yield 21.5 mg (18%); NMR; (400 MHz, d⁶-DMSO) δ_(H) 1.53-1.64 (m, 2H),1.68-1.85 (m, 4H), 1.93-2.03 (m, 2H), 2.19-2.30 (m, 1H), 3.78 (t, 2H,J=7 Hz), 11.20 (s, 1H); m/z 269 [MH⁺]

Example 49 8-chloro-3-(4-fluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-3-(4-fluorobutyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (200 mg, 0.88mmol, 1 eq) in anhydrous DMSO (1 ml) in a 1.5 ml microwave vial equippedwith a stirrer was added sodium bicarbonate (113 mg, 1.07 mmol, 1.2 eq)followed by 1-bromo-4-fluorobutane (114 ul, 165 mg, 1.06 mmol, 1.2 eq).The vial was sealed and heated with stirring using a microwave,maintaining the temperature at 120° C. for 25 min with a maximum poweroutput of 300 W. The resulting dark brown solution was diluted withmethanol (1 ml) and purified by mass directed autopreparative HPLC togive the title compound as a white solid (159 mg, 60%). m/z 301.3 [MH⁺]

-   8-chloro-3-(4-fluorobutyl)-3,7-dihydro-1H-purine-2,6-dione

To a suspension of8-chloro-3-(4-fluorobutyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(100 mg, 0.33 mmol, 1 eq) in anhydrous DCM (2 ml) was added palladiumtetrakis (38 mg, 0.033 mmol, 10% bw), followed by acetic acid (115 ul,121 mg, 2.01 mmol, 6 eq) and phenyl silane (410 ul, 360 mg, 3.33 mmol,10 eq). The resulting light yellow solution was stirred at ambienttemperature for 16 h to give a dark purple solution. The solvent wasremoved under a stream of nitrogen and the residue dissolved in aDMSO/methanol solution (3 ml, 2:1) with heating. The gelatinous mixturewas allowed to cool to ambient temperature, filtered then purified bymass directed autopreparative HPLC to give the title compound as a whitesolid (35 mg, 43%). m/z 261.2 [MH⁺] NMR (400 MHz, MeOD), δ_(H) 4.45 (2H,dt, J=47 and 6 Hz), 4.03 (2H, t, J=7 Hz), 1.90-1.65 (4H, m).

The following compounds were prepared in similar fashion and purified bypreparative or mass directed autopreparative HPLC as appropriate:

Example 50 8-chloro-3-(3-fluoropropyl)-3,7-dihydro-1H-purine-2,6-dione

NMR (400 MHz, MeOD), δ_(H) 4.51 (2H, dt, J=47 and 6 Hz), 4.11 (2H, t,J=7 Hz), 2.18-2.03 (2H, m). m/z 247 [MH⁺]

Example 51 8-chloro-3-(5-fluoropentyl)-3,7-dihydro-1H-purine-2,6-dione

NMR (400 MHz, MeOD), δ_(H) 4.41 (2H, dt, J=48 and 6 Hz), 3.99 (2H, t,J=8 Hz), 1.84-1.63 (4H, m), 1.52-1.40 (2H, m). m/z 273.29 [MH⁺]

Example 52 3-(3-buten-1-yl)-8-chloro-3,7-dihydro-1H-purine-2,6-dione

8-chloro-3,7-dihydro-1H-purine-2,6-dione (100 mg, 0.44 mmol) was stirredwith sodium carbonate (52 mg, 0.49 mmol) in dry DMF (3 ml) for 45 min.,then 4-bromo-1-butene (66 mg, 0.49 mmol) was added and the mixture wasstirred under nitrogen at 40 C for 65 h. After cooling to roomtemperature, the mixture was thoroughly degassed by evacuating thevessel and refilling with nitrogen several times.Tetrakis(triphenylphosphine)palladium(0) (102 mg, 0.09 mmol) was added,the mixture degassed again and then morpholine (0.385 ml, 4.4 mmol)added and stirring continued for 6.5 h. 2M HCl and EtOAc were added, andthe 2-phase system was filtered to remove a yellow precipitated solid.The organic phase of the filtrate was separated and evaporated. Theresidue was dissolved with warming in THF-MeOH (1:1) and loaded onto anaminopropyl SPE (5 g) which was eluted with THF-MeOH (1:1) followed byMeOH and then 5% AcOH in MeOH-DCM (1:1). The product fraction wasfurther purified by mass-directed autoprep to afford the title compound.

Yield 27.5 mg (26%), NMR; (400 MHz, d⁶-DMSO) δ_(H) 2.40 (dt, 2H, J=7 and6 Hz), 3.93 (t, 2H, J=7 Hz), 4.97-5.07 (m, 2H), 5.74-5.85 (m, 1H). 11.22(s, 1H); m/z 241 [MH⁺]

Example 53 8-chloro-3-(6-fluorohexyl)-3,7-dihydro-1H-purine-2,6-dione

NMR (400 MHz, MeOD), δ_(H) 4.40 (2H, dt, 48 and 6 Hz), 3.98 (2H, t, 8Hz), 1.80-1.60 (4H, m), 1.52-1.35 (4H, m). m/z 287 [MH⁺]

Example 54 8-chloro-3-ethyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione

a)8-chloro-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (6 g, 26.5mmol) in anhydrous DMF (30 ml) was added sodium carbonate (3.09 g, 29.15mmol). After 10 minutes stirring at room temperaturemethoxyethoxymethylchloride (3.03 ml, 26.5 mmol) was added and stirringcontinued under nitrogen at room temperature for 66 hours. The reactionmixture was concentrated in vacuo and the residue dissolved in EtOAc(100 ml) and washed with brine (100 ml), the aqueous extract wasextracted with DCM (100 ml) and the organic extracts dried (MgSO₄)combined and concentrated in vacuo. The residue was trituated with EtOAcand the solid filtered off. Concentration of the filtrate afforded alight brown oil that was absorbed onto silica and purified by SPE (Si,50 g) eluting with a gradient of 1:1 EtOAc/cyclohexane-EtOAc to affordthe title compound as a white solid (2 g, 24%), m/z 315.2 [MH⁺]

b)8-chloro-1-methyl-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(2 g, 6.37 mmol) in anhydrous DMF (15 ml) was added sodium carbonate(0.743 g, 7 mmol). After 10 minutes stirring at room temperaturemethyliodide (0.44 ml, 7 mmol) was added and stirring continued undernitrogen at room temperature for 18 hours. The reaction mixture wasconcentrated in vacuo and the residue dissolved in EtOAc (100 ml) andwashed with brine (100 ml). The organic extract was dried (MgSO₄)filtered and evaporated to afford the title compound as a tan oil (85%pure) (2.98 g, quant.), m/z 329.2 [MH⁺]

c) 8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-1-methyl-3-({[2-(methyloxy)ethyl]oxy}methyl)-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione(2.9 g, 6.37 mmol) in dioxan (20 ml) and water (20 ml) was added 5M HClaq. (20 ml). The resulting mixture was heated at 100° C. under nitrogenfor 18 hours. The reaction mixture was then concentrated in vacuo, theresidue was dissolved in EtOAc (100 ml) and washed with water. Theorganic extract was dried (MgSO₄) filtered and evaporated. Purificationby SPE (Si, 20 g) eluting 2:3 EtOAc/cyclohexane afforded the titlecompound as a white solid (1.04 g, 68%). m/z 241.1 [MH⁺].

d) 8-chloro-3-ethyl-1-methyl-3,7-dihydro-1H-purine-2,6-dione

To a solution of8-chloro-1-methyl-7-(2-propen-1-yl)-3,7-dihydro-1H-purine-2,6-dione (100mg, 0.42 mmol) in anhydrous DMF (3 ml) was added sodium carbonate (58mg, 0.54 mmol), after 10 minutes stirring ethyl iodide (0.043 ml, 0.54mmol) was added and the reaction mixture stirred at room temperatureunder nitrogen for 90 hours. Pd(PPh₃)₄ (73 mg, 0.063 mmol) was thenadded and the reaction vessel evacuated and flushed with nitrogen (×3),morpholine (0.37 ml, 4.3 mmol) was added and stirring at roomtemperature under nitrogen continued for 4 hours. The reaction mixturewas diluted with EtOAc (25 ml) and washed with 2M HCl aq. (25 ml). Theorganic extract was dried (MgSO₄) filtered and evaporated. Purificationby aminopropyl SPE (5 g) loading the compound and washing with MeOHbefore eluting the product with 5% AcOH/MeOH afforded the title compoundas a white solid (67 mg, 70%). NMR; d_(H) (400 MHz, d⁶-DMSO) 1.20 (t,3H, J=7 Hz), 3.22 (s, 3H), 3.97 (q, 2H, J=7 Hz), 14.46 (1H, br s); m/z227.2 [M-H]⁻.

All publications, including but not limited to patents and patentapplications, cited in this specification are herein incorporated byreference as if each individual publication were specifically andindividually indicated to be incorporated by reference herein as thoughfully set forth.

1. A method for treatment of type II diabetes mellitus comprisingadministering to a subject in need thereof a therapeutically effectiveamount of a compound which is8-chloro-3-pentyl-3,7-dihydro-1H-purine-2,6-dione

a pharmaceutically acceptable salt thereof.
 2. The method for treatmentof type II diabetes mellitus according to claim 1, wherein the subjectis a human.